401 Unauthorized on /oauth2/token

I am having an issue retrieving access tokens with authorization_code grant type in production. My setup worked fine with the sandbox url & credentials but stopped working when I switched to production from the sandbox values. I’ve double checked the client_id & client_secret several times & tried with multiple generated codes (I also double checked that the code was being requested from the production environment) but was wondering if there is another setting I need to adjust on my developer account to allow this? Here is the request I’ve been sending & the response I’m getting any ideas on what I might be missing would be helpful!

Post URL: https://connect.squareup.com/oauth2/token
Request Body: {
“client_id”: “APPLICATION_ID_HERE”,
“client_secret”: “APPLICATION_SECRET_HERE”,
“code”: “CODE_FROM_AUTHORIZE_CALLBACK”,
“grant_type”: “authorization_code”
}

Response: {
“message”: “Not Authorized”,
“type”: “service.not_authorized”
}

I also tried using the Api Explorer and got the same 401 Unauthorized result

Found the issue! I didn’t realize the application secret under credentials & oauth are different - swapped the credentials application secret out for the one under oauth and now all works!

Ma’am god bless you. Just ran into this same thing. Thank you for helping solve it.