This is possible with a very easy setup. Simply create a primary object then add Attachment as a related object. After you choose it, two Salesforce required fields should be listed. Map the Body Salesforce field on the left with PDF Submission on the right.
By default, the PDF which is sent to Salesforce is the Default Template notification. However, you may create a custom one.
Any custom PDF template you build in the Settings → Notifications → Form Owner tab can be sent to the Attachments object in Salesforce. The template can include images, additional text, and field variables that replace the user’s input from the form.
Submit the form and look for the PDF file in the Notes & Attachments object, related to your primary Salesforce object.
Important Note: PDF templates can’t be sent to the Files object.