It looks like this is a web page, not a feed. I looked for a feed associated with this page, but couldn't find one. Please enter the address of your feed to validate.

Source: https://twitter.com/prostoprosport1/

  1.  
  2.    <!DOCTYPE html>
  3.    <head>
  4.      <title>x.com</title>
  5.      <meta http-equiv="refresh" content="0; url = https://twitter.com/x/migrate?tok=7b2265223a222f70726f73746f70726f73706f7274312f222c2274223a313733323231353335377d13c37b0ce9164604f12badbcc8185f23" />
  6.      <meta charset="utf-8">
  7.      <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=0,viewport-fit=cover">
  8.  
  9.      <link rel="preconnect" href="//abs.twimg.com">
  10.      <link rel="dns-prefetch" href="//abs.twimg.com">
  11.      <link rel="preconnect" href="//api.twitter.com">
  12.      <link rel="dns-prefetch" href="//api.twitter.com">
  13.      <link rel="preconnect" href="//api.x.com">
  14.      <link rel="dns-prefetch" href="//api.x.com">
  15.      <link rel="preconnect" href="//pbs.twimg.com">
  16.      <link rel="dns-prefetch" href="//pbs.twimg.com">
  17.      <link rel="preconnect" href="//t.co">
  18.      <link rel="dns-prefetch" href="//t.co">
  19.      <meta http-equiv="onion-location" content="https://twitter3e4tixl4xyajtrzo62zg5vztmjuricljdp2c5kshju4avyoid.onion/" />
  20.      <meta property="fb:app_id" content="2231777543" />
  21.      <meta content="X (formerly Twitter)" property="og:site_name" />
  22.      <meta name="google-site-verification" content="600dQ0pZYsH2xOFt4hYmf5f5NpjCbWE_qk5Y04dErYM" />
  23.      <meta name="facebook-domain-verification" content="x6sdcc8b5ju3bh8nbm59eswogvg6t1" />
  24.      <meta name="mobile-web-app-capable" content="yes" />
  25.      <meta name="apple-mobile-web-app-title" content="Twitter" />
  26.      <meta name="apple-mobile-web-app-status-bar-style" content="white" />
  27.      <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="Twitter"/>
  28.      <link rel="apple-touch-icon" sizes="192x192" href="https://abs.twimg.com/responsive-web/client-web/icon-ios.77d25eba.png" />
  29.      <meta name="twitter-site-verification" content="AUVDWo1JpbjI22xjTe5JOvTAWuW9bK41CpxYxCeCjH97mEVp7rtiHcvdOaUksJrG" />
  30.      <link rel="manifest" href="/manifest.json" crossorigin="use-credentials" />
  31.      <link rel="mask-icon" sizes="any" href="https://abs.twimg.com/responsive-web/client-web/icon-svg.ea5ff4aa.svg" color="#1D9BF0" />
  32.      <link rel="shortcut icon" href="https://abs.twimg.com/favicons/twitter-pip.3.ico" />
  33.      <meta name="theme-color" content="#000000" />
  34.      <script type="text/javascript" charset="utf-8" nonce="Yzc3YmZhOTQtOGJiNy00YzE5LWE1ODUtYmYzMzJhMzgxMGYy">document.location = "https://twitter.com/x/migrate?tok=7b2265223a222f70726f73746f70726f73706f7274312f222c2274223a313733323231353335377d13c37b0ce9164604f12badbcc8185f23"</script>
  35.      </head>
  36.    <body style="background: #000">
  37.  
  38.    </body>
  39.    </html>
  40.    
Copyright © 2002-9 Sam Ruby, Mark Pilgrim, Joseph Walton, and Phil Ringnalda