I don't think this module is being maintained by the author anymore, however, as I'm completely clueless when it comes to module coding and C/C++ in general, I'd be extremely thankful if someone could lend me a hand in fixing the issues I've found with it:
https://github.com/Polarhigh/AmxxCurl/issues
The latest issue makes this module completely unusable for me and I don't know where to even begin debugging it. Perhaps it's also related to the first one, but I couldn't tell.
EDIT: I contacted the author and he has since fixed the issue