htmlkod='<a href="https://www.tipsport.cz/PartnerRedirectAction.do?pid=3521&sid=4101&bid=35288&tid=6404&rid=1013" target="_blank"><img src="https://ban.tipsport.cz/b/35288.jpg" alt="" title="" width="1920" height="1080" border="0"/></a><img src="https://ban.tipsport.cz/c/1x1.php?pid=3521&sid=4101&bid=35288&tid=6404&rid=1013" alt="" title=""/>';
htmlkod=htmlkod.toString();

var elements = document.getElementsByClassName('tipNRot203');
for(var i = 0; i < elements.length; i++) {
  elements[i].innerHTML=htmlkod;
}