<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $('<a class="btn btn--border theme-btn--primary-inverse sqs-button-element--secondary" href="viber://chat?number=%2B359893452739" target="_blank">Провери наличност</a>').insertAfter('div.product-meta .sqs-add-to-cart-button-wrapper');
});
</script>
<style>
div.sqs-add-to-cart-button-wrapper {
display: none !important;
}
div.product-meta a.btn {
    text-align: center;
}
div.product-meta a.btn {
    flex: 100% !important;
}
div.product-purchase-controls-wrapper {
    flex-wrap: wrap;
}
</style>