Once I aligned both my Event catalog (Gallery) and the Edit Form they were able to recognize one another, I don't have the Error message.
Event catalog: Items & OnSelect property: Filter(colShoppingBasket_Es, User().Email
EditForm: DataSource: Registration List
Items property: Filter(colShoppingBasket_Es, User().Email
I was able to finally show the selected Items from the Event catalog (Gallery) on my Sharepoint List, I updated the Default property for each column, but it only captures the last selected item.
What formula can I use so all selected items will update the SP list?