[keycloak-user] Authorize with local Login Form

[Danny Trunk]

Hello,

my application is Spring Security based.
I've added and configured the Keycloak Spring Security Adapter.
Now I would like to have my own Login page without redirect and 
customizing or adding any Keycloak Themes.

Is it possible to use a local Login Form to authorize on the external 
Keycloak Server?
If so, how to realize it?

I've read something about Bearer Tokens.

Is it the right way?

Can someone point me into the right direction please?