JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="getOrders('138374:order1,738437:order2,927438:order3');">test</button>

JavaScript

function getOrders( orderString) {
   var orders = orderString.split(','); 
   for( var i=0; i < orders.length; i++) {
      var entry = orders[i].split(':');
      alert( "OrderNumber: " + entry[0] );
      alert( "Name: " + entry[1] );
   }
}