Unable to use Keycloak SSO to login to Seafile

I have just setup a Seafile pro server and wanted to be able to use keycloak for sign in. I have followed the manual and the tutorial on the seafile blog, but so far I keep getting the error “Page not found” when I click the Single Sign-On button in the seafile login form.
I have tried multiple links but nothing seems to work. Could anyone give me a tip as to how to make it work?