In case this is useful to anyone else:
I wanted to gain access to the full meetings and token APIs at my-server.com/api/v1/docs/:

Since I was able to access the page above, it looked at first like everything was already set and ready to go!
However, I soon learned that this was not the case:
{"error":"This endpoint has been disabled. Please contact the administrator for further information."}
This made me think that I needed to use the secret in /app/data/api_secret to access the API. But it didn't work (same error message as above).
It turns out I needed to add the following to the /app/data/env file:
API_ALLOW_MEETINGS=true
API_ALLOW_TOKEN=true
Once I restarted the server, I was rewarded with a new error!
{"error":"Unauthorized!"}
This unauthorized error shows up because, I believe, the /app/data/api_secret is not used for the meetings or token APIs. You need to ALSO add the following to your /app/data/env file:
API_KEY_SECRET=yourVerySpecialSecret
Finally, you can click the Authorize button in the swagger / MiroTalk SFU API page (shown above), and add yourVerySpecialSecret to the input box there. After that, you have access to your own MiroTalk SFU API!
Update to add: You can find a complete list of possible env settings here:
https://github.com/miroslavpejic85/mirotalksfu/blob/main/.env.template