Interface 'League\OAuth2\Server\Repositories\AccessTokenRepositoryInterface' not found

Requires "league/oauth2-server" and some other packages. See composer.json.

I am getting the same error PHP Fatal error: Interface 'League\OAuth2\Server\Repositories\ClientRepositoryInterface' not found
the root cause is the vendor directory is getting recreated as my application is running in container so the library "league/oauth2-server" is not being present in vendor and hence the error is encountered while running dbupdate.
Can we keep the library in some other persistant storage and refer from there to autoload.

No, that's not how it works. If you use Docker, for instance, it's your responsibility to add dependent packages each time the container is rebuilt. I usually do it by adding an .sh script in an init folder, then referencing from the docker-compose.override.yml as

    volumes:
      - codebase:/var/www/html
      - ./init/30-composer.sh:/docker-entrypoint-init.d/30-composer.sh

The actual script can call the usual composer require calls but if you want to make sure you only call them unless it's already installed, you can use:

composer show | grep -q foo/bar || composer require foo/bar