<script>
$(document).ready(function(){
$.post("https://xxx.xxx", {
client_name: 123,
user_id: 1,
invoice_group_id: 1
},
function(data) {
var response = JSON.parse(data);
if (response.success == '1')
{
document.getElementById("invoiceid").innerHTML = response.invoice_id;
}
});
});
</script>
<p id="invoiceid"></p>