problem with hs upload

[SMukhhopadhya]

Hello Fellow members,

I am trying to develop a UI extension public app and when I try to do a hs upload I get the following error. Can anyone guide me as to how to overcome this problem. I am unsure how to get/enable the permission for REACT_EXTENSION.

PS C:\Users\suman\hubspot\StripeHubspotTesting> hs project upload
✖ Failed to upload public_app_template project files to stripe-developer-test-account [test account] (48690960)
HubSpotHttpError: Couldn't create a REACT_EXTENSION with your file `/app/extensions/example-card.json` because you don't have access to this functionality. To learn more and sign up for the beta, contact support

[GregDixon]

That Beta being referred to seems to be live now but I'm also still getting this error. I'm not sure what other beta's may be blocking this?

[JOB3]

Hi @GregDixon thanks for reaching out to the community about this ! As @WesQ mentioned, the error:Couldn't create a REACT_EXTENSION with your file `/app/extensions/example-card.json` because you don't have access to this functionality. To learn more and sign up for the beta, contact support

generally means that the target HubSpot account (the portal ID you’re deploying to) is not enrolled in the React/UI extensions beta, or your user doesn’t have the required level of access (typically Super Admin on a portal that is in the beta).  

Super Admin access is required to access CRM Development tools. However, if you have installed the React/UI extensions beta and have Super Admin access already, as a next steps, I would recommend to file a ticket with Support to confirm why the error might still be coming up. 

Cheers, 

Josefina, Community Moderator 

[GregDixon]

Thanks Josefina, yes I am SUperAdmin because I created the Developer account in the first place. The React/UI extensions beta you mentioned just send me to the HS 'All who wander' and support is next to useless, all they do is tell me to join the community and the Slack space. I'm exasperated with how to get this silly error resolved.

[JOB3]

Hi @GregDixon, my apologies- I did not realize you were using a Developer account. It's correct that because custom apps and integrations are heavily customized, they fall out of the scope of Support. But for reference, this is the name of the feature that was shown in the link I provided before; CRM development tools to build UI extensions with React as frontend. Are you able to search for this feature under the Product Updates page in your portal ? I do see the product updates page mentions the feature is available to Developers with access to Sales or Service Hub Enterprises. So it looks like this feature would only be available in Production or Sandbox accounts with Service Hub or Sales Enterprise subscriptions. 

To build and test the React-based UI extensions, you would need an Enterprise customer portal (or sandbox)first. You could then use your developer account + CLI to build the app and deploy it to that Enterprise environment. I would like to tag some experts from our Developer Community @evaldas s @Anton @RubenBurdin  do you have any  additional recommendations to help @GregDixon bypass this error ? - Josefina, Community Moderator 
 

[GregDixon]

Right but that component no longer exists. I need an Enterprise account? No we don't have that. Why does the documentation not specify that? So do I need to upgrade my Development Sandbox to Enterprise level?

[JOB3]

Hi @GregDixon I wanted to clarify that Sandbox accounts and Developer test accounts are two separate features. Sandbox accounts are only available when you already have an Enterprise subscription on your Production account and they mirror your production portal's features and limits rather than being a separate Enterprise plan. On the other hand, Developer test accounts are part of Developer tools access used to build/test apps and are separate from a production portal's subscription tier. Here are two resources which further explain the difference: HubSpot Account Types - Dev Docs  and difference between sandbox and testing account.  Could you provide the link to the docs you're using to implement this feature ? I am happy to request our documentation team to clarify this on the docs as needed.

Also, I have sent you a DM so we can look into your current account set up ( whether it's a dev account, test account or sandbox account)  and confirm the reason for the error. - Josefina 

[GregDixon]

Good morning Josefina. Thanks for the account clarification. That clicks and makes sense. I have now resolved the issue. I was using an out-of-date public sample instead of the newer version 2025.2 (released around August I think). Once I pulled that, then everything worked perfectly. Part of the issue is that I spend time on HubSpot Academy and almost all of that content is out of date and therefore misleading. So at this point I am now unblocked. Thank you for all the help!

[JOB3]

Hi @GregDixon thank you so much for following up on this matter, I'm glad to know the error was resolved on your end! 🙂To confirm, is this the CMS project version 2025.2  you migrated to in order to resolve the REACT_EXTENSION error while using the React/UI Extensions ?  Also, were you able to run this extension on your Developer test account or did you have to use a Sandbox? This information will be very helpful to future community members that run into a similar issue so do not hesitate to list out steps you implemented. 

As per the Academy courses, I can understand the confusion as you were trying to follow those steps but found them to be misaligned with what you were seeing in real time. Please feel free to list the Academy courses you were taking and I'll make sure to ping the appropriate team with your feedback so this can be improved. Thanks again for bringing your question to the community ! - Josefina, Community Moderator 

[GregDixon · Accepted solution]

@JOB3 I think the issue was incompatible calls in the old code. Once I pulled the 2025.2 sample project and upload it, it worked perfectly. No:

1. I went to the client's HubSpot account (the account we are doing the work for) and went to the Developer area in that account.
2. We created the Personal Access Key there
3. We then authorized this Personal Access Key from the CLI at our local development
4. We then uploaded the project to the client's HubSpot account
5. At the client's HubSpot account, we then created a Test Account and installed the project to that.
6. Now we have the sample project installed on the Test account on the Client's HubSpot account and when ready, we'll install it to the client's HubSpot (production) account itself (ours is a private app using UI Extensions to create a Card).

Here is the documentation that helped us through this:

1. Install the CLI: https://developers.hubspot.com/docs/developer-tooling/local-development/hubspot-cli/install-the-cli

2. Creating the App: https://developers.hubspot.com/docs/apps/developer-platform/build-apps/create-an-app

Follow the steps in this documentation and it will work.

[JOB3]

@GregDixon this is genius 💡! Thank you so much for sharing all the steps you took towards the resolution here, your comment  will be invaluable to the community  ! -🚀 Cheers, Josefina 

[AlanGrace]

Did you manage to resolve this? I have the same error at the minute - 

Couldn't create a React extension with your file `/app/extensions/example-card.json` because you don't have access to this beta.

My Production account has Enterprise etc that is required, this error is on my Dev Sandbox but I have the required beta installed.

[GMarques6]

I got the same issue too [ERROR] Couldn't create a REACT_EXTENSION with your file `/app/extensions/example-card.json` because you don't have access to this functionality. To learn more and sign up for the beta, contact support. I've already joined the beta version

[WesQ]

Hello @SMukhhopadhya !

Creating UI extensions with React is currently in beta phase. 

You can follow this link to see your status:

https://app.hubspot.com/product-updates/<Your Portal ID>/all?query=react

You need to go to your HubSpot accounts' "Product Updates" and look for this one, then join the beta:

References: 

• https://knowledge.hubspot.com/account-management/opt-your-hubspot-account-into-a-public-beta-feature
• https://developers.hubspot.com/docs/guides/crm/ui-extensions/create

Was I able to help answer your question? Help the community by marking it as a solution.

[SMukhhopadhya]

Hello,

I already have Beta set as you have described but I think permissions have to be provided from Hubspot's side.

So in summary it still does not work.