Can not create access token for the app connection

we created a private app on HubSpot and used it to create an access token to push data from the Magento platform to Hubspot. But we met the issue below.
- We can authorize data with app information (client id, client secret) and it could redirect to the URL defined on app.
- When using code (return in the redirect URL) to generate an access token, it always returns the result below.
we referred this document to authorize and create access token: Accounts Dashboard | HubSpot
{“status”:“BAD_AUTH_CODE”,“message”:“missing or unknown auth code”,“correlationId”:“0e4d6ed9-da70-4f98-83b3-1d0c3d495434”}

Can someone help me about us

Hey @FTeamUyen :waving_hand: One question to help our community better understand your issue. You mentioned Private Apps and you mentioned OAuth. Can you clarify if you are using a Public App (using OAuth) or a Private App, please?

Best,

Jaycee

hi Jaycee_Lewis

Our client created Private App. And we used it to OAuth.