Accessing NextCloud 20 with older iOS devices? There is no iOS app and the browser doesn't show the login screen

I am unable to login to my local NC instance with an older iOS device (running 9.3.5…it’s old). I used to be able to get the login screen but now I offered a key/token login or a new password, but no login screen. And there are no apps for that iOS release anymore. I get the app not reaching back that far but why no access through the web?

Have you ever been able to solve this issue?

Have any of you ever been able to solve this issue?
iPh5s & iPad Gen4 in an intranet, without any WAN.

I put the iOS provisioning link for CAL and Contacts on a local https-website, then use Safari to browse to:
https://nc-some-intra/remote.php/dav/provisioning/apple-provisioning.mobileconfig

At least this part works well.