There is no way to upload documents that will transmit along with your return. Tax forms like your W-2s, 1099s, 1098s, and other needed tax documents, the program will ask you to enter. But outside of those, there is no way to upload personal documents to transmit with the e-file. If there are other documents that the program doesn't ask for, that you need to send with your return, you will need to mail those in. So you'd need to print and mail the return with the documents.
The address where you will mail the returns should be on the filing instructions sheet that prints out with your return.
