JSFiddle - React, Tailwind, and code Playground

JavaScript

var someObj = {
    3: {
        amount: 30,
        key: 'abc'
    },
    4: {
        amount: 20,
        key: 'def'
    },
};

var res = $.map(someObj, function(v) { return v });
res.sort(function(a, b) {
  return a.amount - b.amount;
});
console.log(res);