Is there any way to upload an attachment to a form in AppSheet that will show up as an attachment in SmartSheet? It is not a column that I can select when I am selecting data.
I have no experience with SmartSheet, so I can’t address your question directly. I can say that AppSheet does not save attachments directly into Google Sheets or Microsoft Excel. Instead, the upload is saved to a separate file storage area and the spreadsheet is updated with the location of the upload in the storage area. I would expect SmartSheet is handled similarly.
Here are some existing docs that reference both SmartSheet and attachments: