Function Type and Function URL?

[tsull360]

Hello,
Really excited to get your solution going, but I'm certainly missing a few fundamentals I could use a pointer or two on. I've created a function and uploaded the solution however I'm unclear on the following:

1. What type of function should I be creating? I've used node.js 18 LTS
2. What is the URL for my function? Is it what's shown on the general tab, or what's shown in 'Get Function URL' in the contact function properties?

When I try with your sample web page, the button does nothing. If I try using postman, I get a 404 error. I know I'm missing something simple, but I can't quite crack the code here.

Thanks!