When you host your server the console should be the first thing to come up... Its the box with the java icon on the bottom right is where your should type the command *op burner624* or whatever your username may be
The problem I am having is that the console doesn't even show up. The server is still running
So i need to know how to do it from the .json file
The spacing and punctuation is important - quotes around each "key": "value" pair, except the number for the Op level. A comma at the end of every line except the last one. See this guide for another example.
When you boot the server up, it'll remove incorrectly formatted entries - check after started the server that the file hasn't reverted back to an empty list (shown as '').