Hello,
Thanks for contacting us and sorry for any inconvenience that might have been caused due to that.
The Noindex option is available in the Advanced tab of the meta box. It seems like you are using the Easy Mode of our plugin. Please follow this guide to switch to the Advanced Mode: https://rankmath.com/kb/switch-from-easy-to-advanced-mode/
Once done, you will be able to access the Advanced tab and set your page as Noindex.
Hope this helps. Let us know if you need any other assistance.
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.