Hello @khahina,
Thank you for contacting the support and sorry for any inconvenience that might have been caused due to that.
The auto nofollow option of the Rank Math plugin works only inside the content area since all the themes are built using different methods.
Sorry to disappoint but that feature is unfortunately not available at this time.
With that being said, there are existing feature requests, so I’ve added your vote to our internal suggestions lists. If your suggestions are something that we’re able to introduce, I’ll be sure to let you know.