Is this very unusual flow possible? (user/password in query parameters)

First, I am very new to keycloak and authentication work.
I know this is definitely something not ideal to implement, but unfortunately to be able to be backwards compatible I am trying to find a way.
The goal is to have the user and password as query parameters in the url:

and get the user to log-in without even seeing the login form.

I wonder even it is possible?
Thanks a lot for any comments and pointers in advance,

Off topic: are you aware of security consequences - Information exposure through query strings in url | OWASP Foundation ?

Thanks for the comment, very good point. I had raised the issue though it was pushed back as the usage is with a narrow scope in a limited environment. That’s why I’m still investigating a possible reasonable approach.