Formatting JSON for browser.storage.local.set

Question

I want to use browser.storage.local.set in a Firefox sidebar extension. I am just new to JSON. I know many computer languages and formats but JSON is so much different from other things.

 

I just want to store a Model with an Id such as SKU1065 and a default Rating of 0 and empty Comments. So I think I want:

{SKU1065: {Rating:0, Comments:""}}

But the following is not working.

var Model = '{"' + CurrentId + ': {Rating:0, Comments:""}}';
browser.storage.local.set(Model);

When I run that code, browser.storage.local.set says it (Model) is not valid.

 

I hope this is very easy for many of you and if so I hope you don't mind providing an answer.