Hey @AMUKHERJEE1010,
As of November 30th HubSpot has sunset the use of API keys. I’m not sure why you are still able to make requests using one but I wouldn’t rely on this as a stable approach moving forward. You should be using the private app access token.
If your request is failing using an access token it’s likely that you’ve included it incorrectly. It should be passed as a header in the request. Are you getting any error messages/response codes back from HubSpot, if you are can you please share?
Also, I’d recommend using the newer CRM Contact APIs instead of the legacy v1 endpoints. Specifically the PATCH /crm/v3/objects/contacts/{contactId} endpoint. You can update contacts using email address as per the below:
