Add custom authentication method

[luboss]

I'd like to use API that doesn't support standard authentication methods (at least not for username/password credentials, permanent API token is not possible in our case for specific reason).
Instead, it expects username and password key:value pairs in JSON payload of POST request. Then it returns temporary API token in access key of JSON response (+ refresh key), valid for 1 hour. The token is used as Bearer Token authentication.
This can be easily set up in Postman, however I couldn't make this work in Infinity plugin.

Could you please consider adding custom authentication method that would enable such mechanism?
Passing credentials in specific form - POST request with user defined JSON passed secret credentials. Then catching token from the response and use it as Bearer Token in subsequent queries?