JSFiddle - React, Tailwind, and code Playground

HTML

<p>Click the button to return the value of the content attribute of all meta elements.</p>

<button id="btn1" onclick="myFunction()">Try it</button>

<p id="demo"></p>

JavaScript

function myFunction() {
  var txt = "";
	document.getElementById("demo").innerHTML = txt;
  // sample url used here, you can make it more dynamic as per your need.
  // used AJAX here to just hit the url & get the page source from those website. It's used here like the way CURL or file_get_contents (https://www.php.net/manual/en/function.file-get-contents.php) from PHP used to get the page source.
  $.ajax({
      url: "https://jsfiddle.net/",
			error: function() {
				txt = "Unable to retrieve webpage source HTML";
			}, 
      success: function(response){
          // will get the output here in string format
          // used $.parseHTML to get DOM elements from the retrieved HTML string. Reference: https://api.jquery.com/jquery.parsehtml/
          response = $.parseHTML(response);
          $.each(response, function(i, el){
              if(el.nodeName.toString().toLowerCase() == 'meta' && $(el).attr("name") != null && typeof $(el).attr("name") != "undefined"){
                  txt += $(el).attr("name") +"="+ ($(el).attr("content")?$(el).attr("content"):($(el).attr("value")?$(el).attr("value"):"")) +"<br>";
                  console.log($(el).attr("name") ,"=", ($(el).attr("content")?$(el).attr("content"):($(el).attr("value")?$(el).attr("value"):"")), el);
              }
          });
      },
      complete: function(){
          document.getElementById("demo").innerHTML = txt;
      }
  });
}