Customizing redirect URL for okta authorization

We developed Okta SAML/Oauth proxy in our company and need to setup Okta OIDC redirect URL in a very particular way so they would redirect users to this proxy first.
Okta redirect URL for twingate seems to be hardcoded to oauth.twingate.com/callback.
Is there a way to customize it?

Second question: Is SAML authentication going to be supported any time soon?