Okta Universal Login and Dashboard App Launch Through Auth0

Currently we use Auth0 for all logins, so would like to continue storing all user metadata on there.

We’d like to build in functionality for our customers so that they can log in with Okta (from our front end but through their own Okta subdomain), or launch our app via the Okta dashboard, then store user metadata within Auth0.

Currently there are two topics that we’d like more information on how to solve.

The first topic: configuring a flow of (our app) -> (Auth0) -> (Okta) -> (Auth0) -> (our app) has been achieved using OpenID. However currently this set up requires manually adding a new connection every time we add a new customer who uses Okta. Ideally what we want is a universal log in, similar to what you see when first logging in to okta, where you enter the domain of your okta account (e.g. mycompany.okta.com). How can this be achieved, without us building domain input on our front end?

The second topic: we’d like our customers to allow their users to put the our app on the Okta dashboard and launch it from there. As Okta makes a push request when launching an app from the dashboard, should the flow be the same as above, but with (Okta) -> ... triggering the initial flow?

Thank you for the help!