Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.
Please note that the link option requires that you have the theme support for that according to these guidelines: https://developer.wordpress.org/block-editor/how-to-guides/themes/theme-support/#link-color-control
In this case, you may need to get in touch with your theme support and ask them if they include support for that.
Hope that helps.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.