Customize a few lines of GitHub code

Gmail2GDrive is a Google Apps Script on GitHub which automatically stores and sorts Gmail attachments into Google Drive folders. See the script here: [login to view URL] I need Gmail2GDrive to perform exactly what it says it does—but I also need it to do a little bit more: - If email does not contain an attachment, save a screenshot of HTML email as .PDF - If email contains an attachment, save ONLY the attachment, and do not save a screenshot of the email. And I need the existing GitHub code customized in the following ways: - the label/gmail folder from which to fetch emails is called "Billing" - filenames of the .PDF files that the script creates should be: "[login to view URL] [login to view URL]" for GMT -6 - the destination folder for files is here: [login to view URL] - the script should be called on a time trigger, once every 15 minutes Message me with any questions. Thanks!