Hi@Alois,
Do you want to export all the selected events to your SP list?
Could you please share a bit more about your SP list data structure, what are the column types of them?
Here is my scenario, you could check for reference.
For that, all the fields in the collection are stored as strings, the key is to convert the data type.
Here is my SP list.

The following is how I collect based on the selected date:
Collect(Events,SortByColumns(Filter(MyCalendarEvents, Text(Start, DateTimeFormat.ShortDate) = Text(_dateSelected, DateTimeFormat.ShortDate)), "Start"))
Add a Button and set the OnSelect property as below:
ForAll(
Events,
Patch(
CalendarEvents,
Defaults(CalendarEvents),
{
Title: Subject,
StartDate: Start,
EndDate: End,
Description: Body,
Location: {Value: Events[@Location]},
Organizer: {
'@odata.type': "#Microsoft.Azure.Connectors.SharePoint.SPListExpandedUser",
Department: "",
Claims: "i:0#.f|membership|" & Organizer,
DisplayName: Organizer,
Email: Organizer,
JobTitle: "",
Picture: ""
}
}
)
)
Note: Event is my collection name. 'CalendarEvents' is my SP list name. Please replace it with yours.
Hope it could help with reference.
Best Regards,
Qi