Thank you for your answer Rose, but i want the line behind the text, not with opacity. That does not seem to look good with the method you provided. Any solution?

Thanks.

Hello, this is already activated, i tried it but no luck, still doesnt work.

Okay, thank you!

The icon changes but the search function is not working anymore, used this:

<?php
add_action( 'wp_enqueue_scripts', 'theme_enqueue_styles' );
function theme_enqueue_styles() {
    etheme_child_styles();
}

add_filter('et_b_search_icon', function() {
        ?>
<svg version="1.1" id="Ebene_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     viewBox="0 0 100 100" style="enable-background:new 0 0 100 100;" xml:space="preserve">
<g>
    <g>
        <path d="M50,57.6c-14.4,0-26.1-11.7-26.1-26.1S35.6,5.4,50,5.4s26.1,11.7,26.1,26.1S64.4,57.6,50,57.6z M50,13.4
            c-10,0-18.1,8.1-18.1,18.1S40,49.6,50,49.6s18.1-8.1,18.1-18.1S60,13.4,50,13.4z"/>
    </g>
    <g>
        <path d="M90.4,94.6c-1.3,0-2.6-0.7-3.4-1.9c-7.7-12.1-21.9-19.6-37-19.6s-29.3,7.5-37,19.6c-1.2,1.9-3.7,2.4-5.5,1.2
            s-2.4-3.7-1.2-5.5C15.4,74,32.1,65.1,50,65.1S84.6,74,93.8,88.4c1.2,1.9,0.6,4.3-1.2,5.5C91.9,94.4,91.1,94.6,90.4,94.6z"/>
    </g>
</g>
</svg>

        <?php
    });

Is there really no way to change the icon?