Implementing Docusign Authentication using Requests

Question

I'm creating an Airbyte connector for Docusign's E-signature Rest API.

Part of the process of implementing a connector is to write an authentication routine that extends the AuthBase class from requests.auth.

The issue is that Docusign does not support refresh tokens for JWT grants. According to the docusign documentation:

The access token granted by JWT Grant expires after one hour, and no refresh token is provided. After the token expires, you must generate a new JWT and exchange it for a new access token.

You can reuse most of the old assertion, just modifying the IAT and EXP values and updating the signature, then submit the updated JWT to get a new access token. Generally, apps that use JWT should get a new access token about 15 minutes before their existing one expires.

However, all of the examples in the "backend application flow" from this part of the requests documentation (which links to this page in the requests-authlib docs) only seem to allow an Auth2 workflow that includes a refresh token.

How can I work around this to make it so that, each time a refresh token expires, a new request is made (with updated IAT EXP, and signature)?