In the preview and publication publish section of the request, you can send a pdf of the request for preview or make a comment to request comments.
Preview
The request and , together with the attachments and links added to it, go to the recipient(s) of the message preview as an attachment to the e-mail message.
Request for comment
if comments are requested with the function, a If the box marked “Request comments” is marked, an email message containing a link to the commenting interface comment thread is sent to the recipient of the message by e-mail by clicking this link, you
By clicking the link that is sent, the recipient can go to the commenting view comment thread and send comments . regarding the request.
...
Click "Send a preview by email" and in the window that opens define:
Select "Ask for comments" if you want comments from the recipient
Define a comment deadline
"Recipients": enter or copy/paste email addresses separated by line breaks here
"Sender's name": enter here the name you want to appear as the sender of the email
"Message subject": enter here the text you want to appear as the subject of the email
"Message": enter the actual message/text of the e-mail here, you can edit the default text
Send a comment request by clicking the "Send message" button
Recipients will receive an email with a link to the comment interface
Commenters must send their comments by the set deadline
...