Hi Captain

You can currently share a page to then save it to .pdf which can then be emailed or otherwise transferred to another device to print.

Printing directly from Firefox for Android is currently not available but may be included in a future update.

I'm sorry, but this is a basic feature. You can't expect every day users to know how to do all that to print. At least in Chrome it's only a couple of steps. As a programmer I know it wouldn't take that much.

I just noticed it's already enabled, at least in Firefox Nightly for Android.