I’m assuming thru Kodi (formerly known as XBMC). You’ll need to install it on the FireStick then install some Addon programs. Note that this is technically illegal content, so you should use a VPN.
Edit: I was replying as I read thru the posts. FYI...installing Kodi on the Firestick is pretty simple, just google it. However, getting good/stable streams can be hit or miss. If you're looking for a straight-forward flawless solution, this probably isn't it. If you don't mind some troubleshooting and tinkering around from time to time...it's certainly worth FREE (outside the cost of the Firestick and VPN service).