I want to setup a reverse proxy at my Job which on the fly injects credentials into requests.

Usecase:

We are using the Facebook Marketing API for quite some stuff, but basically every developer in the company needs API credentials for it. I want to secure this better and have the API credentials only saved in the reverse proxy service. So devs connect to the service and can use the authenticated Facebook Marketing API without ever getting hold of the API credentials.

Do you know of a reverse proxy that can do that?