The restricted page is showing as No Permission for the users who do not have permission to the page. Do Confluence have any option to send a request to the space owners directly from the restricted page like the share point is having the option for this? Do Confluence have any feature that is to be enabled for this?
Good point. I reproduced this and can confirm there is no request button. At least there is an explaining text below the "No permission" saying
This is because it's inheriting restrictions from a parent page. A space admin or the person who shared this page may be able to give you access.
if the users in question have access to the space where the restricted page is located, they'll see a button to request access to the page when navigating to the page. See https://confluence.atlassian.com/conf713/page-restrictions-1077913203.html#PageRestrictions-Getaccesstoarestrictedpage for details.
If a user doesn't have permission to view a page, then how can he/she request access to see it? The only way you could do that is if that page had edit restrictions only. Then the user would be able to view it and ask from the space admin permission to edit it.
But no, there is no such button to request access.
EDIT: After seeing Nicolai's answers, I really had to delete the last sentence! Seems that I missed the fact that someone else could provide you with the link. Then request access would make sense.