You can send documents you create in Formstack to be signed through Learn how to make a document in Formstack.Sign.
How to upload a document to Dropbox Sign
There are two ways you can send a file you’ve created on Formstack for signatures viaSign.
If these don’t work, you can use the “File attached to Record” method with a template file source from Formstack. Learn more about how to use a template file.