How do I add an Upload File field in Microsoft Forms?
Upload files in a survey
Upload Files in Microsoft Forms
Warning: The feature to upload files only works when sharing the form internally within the organisation. You cannot use this field for public / anyone can respond forms.
Tip: To receive files from external people (without a diocesan account), you can use the Request files feature in SharePoint and paste the request file link in your Microsoft Form. For a guide on how to do this please see the following article: