Use this link, they are the easiest: https://www.knowledgehut.com/blog/web-development/stripe-node-js#6.-setting%C2%A0up-the%C2%A0frontend%C2%A0 If you want to do the server in ES6 syntax, I recommend copying the legacy JS code from the link above, and just asking chatGPT or something to convert it for you...saves you the hassle.