Github personal token Login don't expire

I am logging using Github auth method , with Cloud storage backend, and i want Github personal tokens to expire in 20 mins once login in vault and need to generate a new personal token every use after certain expiration . I have tuned the default lease to 2mins for the auth method enabled at "github/ (path) to check if its working , still no luck .

Can you please help me how do i implement this ? Thank you