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.
The notice should be cleared once you have set a redirect or just click the x
button on the notification.
If it’s still not getting removed, clear your website’s cache and the transients at Rank Math > Status & Tools > Database Tools > Remove transients

Please note that some options are only available when you enable the Advanced Mode in Rank Math. If it’s not showing, you must have chosen to use Easy Mode. Please follow the steps in this link to switch to Advanced Mode:
https://rankmath.com/kb/advanced-mode/
Let us know how this goes.
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.