I do integrate API sometimes into my products. My latest API integration as well as API redistribution is at https://trackmybot.com which is using the POST method.

Before this, I'd built https://bunnyapi.com which used a purely GET method.

Once you learn how to build an API, it's straightforward and not a pain at all. I use https://curlconverter.com/ to do the API which returns it in any language you need it in.

Then just read in the request, check the key if you have one, along with all the other instructions.