URGENT! SITEMAPS COULDN’T FETCH

I got a website that already been check all the possibilities that would go wrong that causing the site maps couldn’t fetch in GSC. and i check back after few days. it still couldn’t fetch. i try to go url inspection using the sitemaps. and i go for url live test. it showing the page fetch : Successful. below it is Indexing allowed? : No: ‘noindex’ detected in ‘X-Robots-Tag’ http header.

But if i go to google search and type site:example.com. it show the entire website things. but with the previous title and meta. which before i take over this website and before i connect it to GSC.

what can i do to make sitemaps submit successful and start to do the keyword research. PLEASE HELP ME!