Ajouter Google Tag Manager à WordPress grâce à ACF

<?php
if( function_exists('get_field') ){
	$tag_manager = get_field('tag_manager', 'option');

	if(!empty($tag_manager)){
		add_action( 'wp_head', function () use ($tag_manager){
			?>
			<!-- Google Tag Manager -->
			<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
						new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
					j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
					'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
				})(window,document,'script','dataLayer','<?= $tag_manager ?>');</script>
			<!-- End Google Tag Manager -->
			<?php
		}, 1 );

		add_action( 'wp_body_open', function () use ($tag_manager){
			?>
			<!-- Google Tag Manager (noscript) -->
			<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=<?= $tag_manager ?>"
							  height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
			<!-- End Google Tag Manager (noscript) -->
			<?php
		}, 1 );

	}
}