please assist me to add google ads on my websitei tried they arent showing :     i wish to get a guide on how to add google ads on html of my website i tried they are not showing
    
    <!DOCTYPE html>
    <html>
    <head>
    	<title>WEB DEVELOPMENT TUTORIAL</title>
    	<link rel="stylesheet" type="text/css" href="style.css">
    </head>
    <body>
    	
    	<header>
    		<div class="main">
    			<div class="logo">
    				<img src="logo.jpg">
    			</div>
    			<ul>
    				<li class="active"><a href="#">Home</a></li>
    				<li><a href="dailyposted.php">DAILY BETTING TIPS</a></li>
    				<li><a href="megaposted.php">MEGAJACKPOT PREDICTIONS</a></li>
    				<li><a href="midweekposted.php">MIDWEEKJACKPOT PREDICTIONS</a></li>
    				<li><a href="https://www.goal.com">TRANSFER NEWS</a></li>
    			</ul>
    		</div>
    		<div class="title">
    			<h1>SURE DAILY BETTING TIPS</h1>
    		</div>
    		<div class="button">
    			<a href="#" class="btn">WATCH VIDEO</a>
    			<a href="#" class="btn">LEARN MORE</a>
    		</div>
i tried to add google auto ads here. The website shows nothing even after 4 hours.please help.is there any test ads for website please aslso
    		<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
    <script>
         (adsbygoogle = window.adsbygoogle || []).push({
              google_ad_client: "ca-pub-2870870041610409",
              enable_page_level_ads: true
         });
    </script>
    		</header>
    </body>
    </html>