Calendar Issues

Hello, Im having trouble with calendars. I have a proton mail calendar. I have 4 deck board calendars with most of the important information in.

I would like to see all these calendars on my phone.

If I connect my nextcloud calendar to anywhere, either proton calendar directly or on my iOS device as an account. I only get my personal calendar that has nothing in it. I need to copy or duplicate events from the deck board calendars to my personal calendar for this to be useful to me but dont think this is possible?

Issue with connecting to proton, i can only add my personal calendar as read only. If i try to add personal calendar with credenitials it doesnโ€™t ask for creds and then fails at syncing. Am I missing something? Maybe a question for proton community.

iOS doesnโ€™t have this issue and adds the RW calendar fine with credentials. But as said before the calendar is empty.

Does anyone have any tips on how I can get all my deck calendar events and proton mail calendar in one place on my phone?

So far the only place for my nextcloud deck calendars is the web page calandar app.

either i connect all to proton and use their proton calendar app - or i connect them individually to my iOS device as an account.

Think a nextcloud dedicated calendar app is needed.