This module is an the AnyEvent manpage user, you need to make sure that you
use and run a supported event loop.

This module implements a simple, stateless and non-blocking HTTP client. It
supports GET, POST and other request methods, cookies and more, all on a
very low level. It can follow redirects, supports proxies, and
automatically limits the number of connections to the values specified in
the RFC.

It should generally be a "good client" that is enough for most HTTP tasks.
Simple tasks should be simple, but complex tasks should still be possible
as the user retains control over request and response headers.

The caller is responsible for authentication management, cookies (if the
simplistic implementation in this module doesn't suffice), referer and
other high-level protocol details for which this module offers only limited
support.