Allow comments on a Google Doc by anyone with the link
1. Open your Google Doc.
2. In the upper right side of your screen, click on Share.
3. Next to Anyone with the link can view, click the down arrow and click More.
4. Click the down arrow next to Access: Anyone and select Can comment.
5. Click Save.
6. Click Done.
7. Getting an "Are you sure?" message?
7.1. If you are sending to an email address that is not Gmail, you will get a message that anyone with the email invitation will have access to your documen. Click Yes.
7.2. If you are sending to a Gmail address that is not in your "organization," you will get a message checking to be sure you want to share your document. Click Yes.