This code demonstrates how to buy a fungible token on the XRP Ledger's decentralized exchange (DEX). For a detailed explanation of how to trade using the DEX, see https://xrpl.org/trade-in-the-decentralized-exchange.html.
The code is designed to run in a browser by loading demo.html and watching the console output, or in Node.js. For Node.js, you must first install the dependencies using your preferred package manager (such as yarn or npm).