Modification of websites

I´m looking experienced programmer which could to repair my xml sitemap. Currently in Google search console is stated "general http error" and I need to repair it. I tried remove blocked urls from robots.txt. file but there still this error.

Also I need to implment my own GDPR and Cookies consent. I can to provide jquery script for it and next I need to implement age restriction jquery script for some categories on my websites.

https://www.jqueryscript.net/other/Website-Age-Verification-Plugin-with-jQuery.html
https://www.jqueryscript.net/other/GDPR-Cookie-Consent-Popup-Plugin.html