Back up iPhone calendar to iCloud and share with iPad

I recently got an iPhone 16 Pro. All my apps were moved onto the new phone with no problem. When I look at iCloud, none of my calendar entries are displayed and they don't replicate to my new iPad. When I look at calendars, it shows that all the entries on my calendar are 'On my iPhone". How can I move/copy all the calendar events from my iPhone to iCloud? When I log into iCloud on my laptop, there are no entries on the calendar.