Native mobile with PKCE and Custom Login page ( no widget )

Morning. We have existing native ( iOS and Android ) mobile applications along with a number of web based services using OIDC and SAML applications and want to move to a central fully custom login page without using the Okta widget ( UI reasons ).

I have the web based apps covered for login, but the existing native mobile applications, I can’t see how they will work with a custom hosted login page and I wondered if someone could point me in the right direction.

  1. How will the app redirect to the custom hosted page in place of the Okta login page. Do I handle that manually in the app ( not preferred as I’d like to migrate without having to update the apps )
  2. How can the custom hosted login page handle the code verifier and state/nonce generated by the app during the OIDC /authorize request ?

we have a few samples for using a custom login page instead of redirecting to okta; hope these help