Authenticate a User for IAP

I found this documentation how to get a token to access IAP protected resources from command line: https://cloud.google.com/iap/docs/authentication-howto#signing_in_to_the_application

I could not figure out how to use oauth2l to get the same token. Can this be done?

I would like to add this step to a script that our Devs are running when developing locally but running nc and extracting stuff from a url is not something I want to do on my own :)