Hi @sbgoh ,
Do you want to export data from powerapps to excel or sharepoint ?
I'm afraid it's not supported to export data from powerapps.
Please notice that:
powerapps app is just an app. It is not a data source. It could not store any data. So there's no data that you could export.
You could only export app from powerapps app.
If you want to export data, you need to export from a data source.
If you want to export data from sharepoint to excel, you do not need to use powerapps.
In sharepoint, there's already a feather about this:

If you want to trigger this feather by clicking a button in powerapps, you could consider using collect function.
Firstly collect all the data from sharepoint list to collection. Then use collect function to save all these data to excel.
Just like this:
Collect(collection1,listname);
Collect(exceltable,collection1)
Best regards,