Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
This entry on the robots.txt file should not cause any worry, it just tells the bots not to index the files on wp-admin.
Could you please login to the search console and ensure that you have submitted the correct sitemap file ie https://domain.com/sitemap_index.xml
Looking forward to helping you. Thank you.
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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.