On the workspace, tap on the card with the « + »;
Tap on the button with the cloud icon;
Tap on Add new;
Select the Excel file (.xlsx) you wish to add within the list;
Verify that everything on the shown form is correct;
Tap on the floppy disk icon to save it and send it in production;
The form will now appear in the list of available forms after pressing on the card with the "+" icon on the workspace. You can now open the form to complete it.