How to add NextCloud Calendar to iphone

Hello, I have tried all steps listed in this thread, plus the steps in your most recent comment to create an app-specific password. However, I am still unable to add the CalDAV to my iOS devices (iPad with v15.6 and iPhone with v17.3.1). If it’s not too much trouble, would someone please write how to connect step-by-step inside the iOS “Add Account” dialog? I’ve tried every conceivable variation of server, username, password - nothing works.