3 legged Authorization

[asim771]

Respected Sir!
Hope you are fine.
I have already implemented 3 legged authorization using c# in a startup.cs class which is working fine. Now I want I can send a login request when any user hits the APP controller then the request needs to be generated and the access token will return in the same controller after this I can show a view to the user where he can type Number and SMS then click on the send button.

So if you have a solution kindly help me or guide me on how I can do this.
Thanks