Action button that saves a file to specific location

I am attempting to add an action button to a fillable PDF that will specifically save to a drive on dropbox. The person I would like to interact with the document on a regular basis is not computer savvy and I would like to avoid having her manually selecting the location when the save as button is clicked.

I am not too familiar with creating scripts but would be willing to learn, just having trouble on where to start. Does anyone have any suggestions?

Extra credit if the form can be named as one of the fields on the document. As example the document would be saved as [Random Last Name] which would be pulled from the last name field on the document.

Thank you in advance!