API edits on Windows

I want to add a bit of text at the beginning of the body of some of my notes. I suppose the API is the right tool for that, but still a bit confused on how to run it.

Do I have to operate from within a server? Could it be a web service, like IFTTT (sorry if that sounds lame to y’all programmers).

Or could it all be done locally (hopefully), and if so, where do I put the code? cmd? Some browser plugin or console?

Joplin 1.0.214
Win 10 1909

Is there something not clear about the documentation? https://joplinapp.org/api/

You need to know what a REST API is, but beyond that there’s nothing very tricky about using the API.