Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
We recommend to use the meta name= “robots” tag to prevent your thank you page from being indexed. And in more detail, to use the “No Index, Follow” attribute. It looks like this:

You can check if the meta of your thank you page looks like this
<meta name=”robots” content=”noindex, follow”>
Using this tag results in your confirmation page not being indexed. The “follow” attribute allows the search engines to follow the links on the page and better crawl your website.
More information on how to Noindex URLs, you can check our Knowledgeable article: https://rankmath.com/kb/how-to-noindex-urls/
I hope that helps and please don’t hesitate to get in touch if you have any other questions.
Hello,
as you can see in this screenshot https://ibb.co/RQwcCc7 the page still pops up in search results.
This is the page in back end.
Not sure what I’m doing wrong… see: https://ibb.co/12vcyMC and https://ibb.co/MsQNVyj
Best wishes
Lorenzo
Hello,
If you have recently changed the robots meta of that page to noindex, it may take some time for Google to remove them on the search results page. Unfortunately, there is no exact time when will Google recrawl your site to read the page that is already noindexed.
In case you wanted it to be removed immediately, you can use the page removal tool in your Google Search Console account. This should take about 24-48 hours to remove the URLs upon submitting.

Here’s a link for more information:
https://support.google.com/webmasters/answer/9689846?hl=en
I 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.