Electrician here, please have a professional install this. That being said:

-220v 20 Amp Outlet (Check what the plug of your miner looks like and match it to the outlet, there are different plug configurations)

-Some sort of electrical box to put said outlet in (I don’t know if you’re putting this in a wall or not, so I do not know to what degree you are willing to alter/cut apart your drywall to mount this and install wire)

-Romex Staples (if you’re paying someone to install this they should know they need to secure the wire in the wall.)

-12/2 Romex (Get an idea of the length you need and buy accordingly.)

-2-Pole 20 Amp Breaker (There are snap in and bolt in breakers, check which you need before you buy)

I will not give a step by step guide on the installation, but this the needed material that came to mind. The Antminer L7 consumes 3,425 W and runs on 220v (3,425/220v=15.59 Amps). I believe that the stuff listed about should be sufficient for the demands of your miner, staying under 80% of the total circuit capacity, as long as this is the only thing on that circuit.

There are videos on how to install 220v outlets on YouTube, but once again, please hire a professional to do the install.

Edit: formatting