On your side, you should create corresponding SP List for the related collection data source. Then add these SP Lists as data source into your app. Within your SP List, for the date column header, you should create a Date type column to store its value, for other column headers, you could create a Single Text type column to store value.
Please consider take a try with above solution, check if the issue is solved.
Community Support Team _ Kris Dai If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
I have changed the confirmation screen OnVisible to link to the SP list. The name of the list is LeaveRequest
I have added the screenshots for these as attachments. Can you check that I'm going in the correct direction.
I cant actually test the leave request app as when Im creating a new request I cant seem to click on a name in the GalleryChangeApprover when selecting a user to "submit a request" The name will highlight but not actually select