Hello,
There’s a difference between a robots.txt file and robots meta tag. Kindly go through this article: https://www.sistrix.com/ask-sistrix/google-index-google-bot-crawler/robots-meta-tag-vs-robots-txt-what-are-the-main-differences
I tested your page URL with the Mobile-friendly Test tool by Google and it is able to crawl and ready to index this page.

I also checked your robots.txt and it does not block any page from indexing.
It is up to Google now when it decides to index this page. Please wait for a while and see if this fixes your issue.
Please don’t hesitate to contact us again if you have any other questions.
Thank you
I faced the same issue. Instant indexing plugin doesn’t work well for resolve issues like “Crawled-currently not indexed” and “Discovered-not indexed”. for non-Wordpress I used other solutions from Github and it solved all these issues.
Seems this Instant indexing plugin works well only for the new URLs..
You did not read the query correctly. Read it, try to understand what I want to say then reply.
Try to read carefully my answer. You can believe me, that I read all this threat with all answers from support. Read again my answer, think, try, say thanks…
I have enabled No-Indexed in Robots.txt in this page https://downloadandenjoy.com/cookies-for-grammarly/ using rankmath plugin. But when I check the page in robots.txt validator it is showing indexing allowed. please check.
Hello,
I can check that the page is set as noindex:

Please try checking the page with the URL Inspection Tool of GSC instead of the robots.txt validator.
Let us know how that goes. Looking forward to your update.
Thanks.
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.