socket.io and file creation

I'm guessing I can use Cloudflare API for this, but there is a game on my site when you can write JavaScript code and can see the output in a window. I have a few buttons where you can save your projects, and load other people's creations by entering a project ID. I was wondering how I can create .js files to save/load projects, and how I can transmit data from the client to the server without using Socket.io assuming Cloudflair does not support that. She screenshot shows how a project gets saved (server-side code) before I switched to Cloudflair.