Why do you not want to answer this thread?(Your answer will be sent to Jeanette and Aytekin)
Yes. You can use Upload field on the form to allow the form user to upload file/document using the form.
User guide: Which-file-types-are-allowed-for-the-upload-field
You can even integrate the form to Dropbox or Google drvie app and it will still be part of the form process.