Hello,
Thank you for contacting Rank Math and bringing your concern to our attention.
Removing your site data from Google SERPs entirely is a time-consuming process. It may take a long time to de-index your site URLs from Google SERPs, as Google is notoriously slow at de-indexing URLs.
However, if you wish to remove your site from SERPs, you may try following the steps below:
#1 ~ set noindex
tag to your entire site URLs. You may tick the option Search engine visibility from WordPress Dashboard > Settings > Reading. This should automatically set noindex tag to your entire website automatically.
#2 ~ Remove your sitemaps from GSC.
#3 ~ Or you may also remove your site property entirely from Google Search Console.
Hope that helps, and please do not hesitate to let us know if you need our assistance with anything else.
Thank you.