I got an html tag error on Google webmaster tools when I link to my Facebook page using this structure "fb://page/id" on my amp based website.

The error shows Invalid URL protocol 'fb:' for attribute 'href' in tag 'a'. Please help me to solve the issue. Can you whitelist Facebook links which using the structure "fb://page/id"?

The advantage of using Facebook is when someone click on the link from mobile browser, it opens Facebook app instead of open the link in browser.

Thank you so much