This is a playground to test JavaScript. It runs a completely standard copy of Node.js on a virtual server created just for you. Every one of npm’s 300,000+ packages are pre-installed, so try it out:
const fs = require('fs');
// Create a file, so we can read it.
fs.writeFileSync('/tmp/CatWorried1.jpg', "this is a text about a worried cat...");
// To add image to post
var FormData = require('form-data');
var formData = new FormData();
// Fill the formData object
formData.append('dum', 'dum');
// load picture image
formData.append('my_file', fs.readFileSync('/tmp/CatWorried1.jpg'));
var aBuff=formData.getBuffer();