Keycloak seems complicated, but it's actually not that complicated if you use it for simple OIDC provider.
Just create a new realm, then go to client -> create. Enter your client-id, with openid-connect as protocol. Then, set access type to "confidential", set valid redirect uri to "https://" (or even "https://*" if you're lazy and want to use it on multiple apps). Then hit save and go to the credential tab to copy your client secret. Then head to "users" menu to start adding users to your realm.
That's the basic setup which should be good for home use. The good thing about keycloak is, as you grow your homelab, whatever stuff you may need later can be provided by keycloak. Want some users to have access to app A, but not app B? 2 factor auth? Allow users to login with google account? Heck, allow users to login with another sso provider (chaining)? You can do pretty much anything.