Example Steps to create field to save Google Doc URL to “Opportunity” Record:

1. Setup

2. Customize “Opportunity” object

3. Create New Custom field

4. Field type is URL (Label field Opportunity Doc URL or something unique)

5. Click through steps to save new field and then copy API name, should look like Opportunity_Doc_URL__c

6. Go back to document action and paste this API name (without quotation or merge field brackets around it) into field labeled “Save URL to Salesforce Field.”

7. Now go back to example Opportunity record to click custom button to merge document

8. After document is generated, the URL field will be populated on record.

9. Click URL link to edit document from opportunity record which will display in new window

10. Once edits are completed, you can then download as PDF and attach to record or follow steps to create a custom button or link with a formula that would include the google doc id and then parameters at the end to export and download as a PDF.

If you want to email a link to your google doc for PDF download, you can review this article.