Got Http response code 401 when accessing https://api.paypal.com/v1/oauth2/token.
A HTTP401 on /token is returned if the client_id/secret aren’t recognized
(either the wrong credentials for the environment, or the credentials aren’t
active).
Can you run a test via cURL to rule out any environment / code-specific issues?
curl -v -u "client_id:secret" "https://api.sandbox.paypal.com/v1/oauth2/token" -X POST -d