manage-consent-button.php

<?php

defined( 'ABSPATH' ) or die( "you do not have acces to this page!" );

/**
 * 1. Make sure you use the Font-Awesome 5 Library. A free plugin with the same name is available for download.
 * 2. Do NOT hide the current Manage Consent Tab under settings.
 * 3. Change CSS if so desired!
 */

function myCustomManageConsent() {
	?>
	<div id="manageconsent" class="cmplz-show-banner"><i class="cmplz-fas fas fa-cookie-bite"></i></div>
	<style>
        #manageconsent {
            font-family: "Font Awesome Free 5";
            position: fixed;
            cursor: pointer;
            width: 60px;
            height: 60px;
            bottom: 40px;
            left: 40px;
            font-size: 30px;
            background-color: #29b6f6;
            color: #fff;
            line-height: 2;
            border-radius: 50px;
            text-align: center;
            box-shadow: 2px 2px 3px #999;
        }

        #manageconsent:hover {
            background-color: #333;
            color: #fff;
        }
	    .cmplz-manage-consent {display:none;}
	</style>
	<script>
        document.addEventListener('click', '.cmplz-show-banner', function(){
            document.querySelectorAll('.cmplz-manage-consent').forEach(obj => {
                obj.click();
            });
        });
	</script>

	<?php

}

add_action( 'wp_footer', 'myCustomManageConsent' );