When I started blogging on Wix I was a bit amazed that the code snippet tool that the editor has is lacking the basic features, like line numbering, and syntax highlighting, and was even missing the copy button.
After searching for a while on the web, I came across the use of Prism in Wix but it was static, meaning it didn't auto-generate the snippet.
Although I cannot modify the code in Wix, I've created this tool to auto-generate the boilerplate code so that you can add code snippets easier.
All you have to do is to paste your code here (I won't steal it), select the appropriate settings, press the button, and then, on your own site add an HTML element and paste. And you're done.
Hope it helps you as much as it is helping me now.