How to optionally add Oauth "Login dialog redirect" parameters?

I am building a plugin to integrate auth0.com, and I’m currently setting up the Oauth User-Agent Flow so I can use the workflow action “Signup/login with a social network”:
Screen Shot 2021-01-31 at 10.50.32 am

This is the standard Login dialog redirect URL: https://YOUR-DOMAIN-HERE.auth0.com/authorize

But to show the signup page (not the login page) you can append the parameter screen_hint=signup to the Login dialog redirect URL: https://YOUR-DOMAIN-HERE.auth0.com/authorize?screen_hint=signup

What I can’t figure out is how to optionally add the screen_hint=signup parameter.

At the moment I have to choose to always have the parameter included or never have it included by deleting it entirely. There is no option to include or exclude the parameter each time I use the “Signup/login with a social network” action.

I want the option to include or exclude the parameter because sometimes I want the workflow to the show the login page, and other times I want it to show the signup page.

One workaround I found is to create an entirely new Oauth User-Agent Flow using the API Connector (or even an entirely new plugin API setup). That way I have one Oauth User-Agent Flow setup with the screen_hint=signup parameter and one without. But that is cumbersome and comes with it’s own limitations.

Is there a better way?

Turns out that workaround is not realistic, because any extra API calls are tied to the original Oauth User0Agent Flow. This makes the workaround unmanageable.

Does anyone have another solution?

Still scratching my head about this one :thinking: