You have to initialize and use gr.insert();

Please see below code for reference:

In your widget server code you need to put

line 22: gr.initialize();

&

line 38: gr.insert();

var gr = new GlideRecord('to_do');
gr.initialize(); 
gr.name = 'first to do item'; 
gr.description = 'learn about GlideRecord'; 
gr.insert();

You can read more about this in below 

https://developer.servicenow.com/app.do#!/api_doc?v=newyork&id=r_GlideRecord-initialize

Mark as correct if this helps!!

-Vinay.