<div id="liqpay_checkout"></div>
<script>
    window.LiqPayCheckoutCallback = function() {
    LiqPayCheckout.init({
    data: "DATA-from-server",
    signature: "SIGNATURE-from-server",
    embedTo: "#liqpay_checkout",
    language: "ru",
    mode: "embed" // embed || popup
    }).on("liqpay.callback", function(data){
        console.log(data.status);
        console.log(data);
    }).on("liqpay.ready", function(data){
        // ready
    }).on("liqpay.close", function(data){
        // close
    });
};
</script>
<script src="//static.liqpay.ua/libjs/checkout.js" async></script>