If you would like adding jQuery to the KWIZ Apps JS Script Editor, please follow the steps below; 

1. Download you jQuery (for example: https://jquery.com/download 
2. Create a new subfolder jQuery in SharePoint Site Assts and save jQuery file there. 
3. Create a JS file name 'YOURLISTID_loadjquery.js' with the script below

You can find the correct LIST ID in the script editor HELP section:

Script to copy: 

if (typeof jQuery == 'undefined') {
    var script = document.createElement('script'); 
    script.src = "/YOURSITE/jQuery/jquery.min.js"; 
    script.type = 'text/javascript'; 
    script.onload = function () { 
        $(document).ready(function() { 
            // Your jQuery code here 
            console.log("jQuery loaded and ready to use!"); 
        }); 
    }; 
    document.head.appendChild(script); 
} else { 
    $(document).ready(function() { 
        // Your jQuery code here 
        console.log("jQuery was already loaded."); 
    }); 
} 

Then you can use your jQuery in our API in script editor.