sync ios with nextcloud calendar/contacts

sync ios with nextcloud calendar/contacts

I have created a profile which syncs an iPhone with a nextcloud calendar and contacts. Because of to the %username% variable it works for all users. Unfortunately I cannot enter the password for the nextcloud in the profile - it is of course different for each user.
So the user has to enter the password before she can use the calendar.
But whenever I update the profile and push a new version to the devices, the password dialogs pop up again. That is very annoying.
How can I improve this situation?
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