400 Bad Request - Missing Client ID (or client_secret) when refreshing token

Hmm not sure if I follow 100% (still learning), so let me re-phrase my question:

  1. I have ‘static’ client_id and secret_id assigned to my account. They never change for my app (unless I forget my secret_id and need to create a new one. That’s understandable.

  2. Because I want to increase my request limit from 30 to 120, I decided to get an Authorization Token (Bearer Token). Unfortunately, this token does not have a pre-assigned refresh token which I could use to run this request:

   --data-urlencode
   ?grant_type=refresh_token
   &refresh_token=<your refresh token> # I don't have this one
   &client_id=<your client ID>
   &client_secret=<your client secret>

Is there a way to refresh my Bearer Token then in a server-to-server API “integration” or should I simply request a new Bearer Token every time my old one expires?

PS: Thank you for your patience and support!