Cluster, Reverse Proxy and SSO confusion

Greetings everyone , im sorry to bother you but I am in some need of experience in setting up the sso for incus ui. I would be eternally grateful if someone could take some time to help me out…

my setup is a 3 node cluster (no-load balancing yet. but I plan to use haproxy after I get the incus-ui working via my reverse-proxy setup), I am using nginx proxy manager to reverse proxy into the leader node (which just sends me to the incus ui setup page with the certificates).

I have followed this tutorial to the best of my abilities to setup auth0 for sso integration

but I fear I may have made a mistake when it came to the callback urls… for my nginx reverse proxy manager I just have it as incus.mydomain.com which routes to https internal lan address which works fine to get to the incus ui setup page… but if I click on login via sso I am just stuck on a white page. Can anyone shed some light into where I made my mistake?