How to install a BOT on Lichess?

Hello! I want to create a new account and run a bot there. I'm trying to use this instruction: github.com/careless25/lichess-uci-bot, but when I run "pip install -r requirements.txt" (and with specified path too) in cmd it says that "pip" is not recognized as an internal or external command, operable program or batch file.
I have Windows 7, 64, Chrome.

And also a question: is it possible to use only one type of engine per account? Or I can use any engine, if my account has "BOT" in its name?
And is using an engine against a bot considered cheating (I saw some people do that)?

@Chesstroll_Ingot You need to install python, pip, and possibly other dependencies I'm unaware of.

BOT accounts need to follow the Lichess terms of service (in terms of rating boosting/sandbagging, etc.) but I assume it's fine to have an account which uses one engine for bullet, another for blitz, a third for atomic, etc.

re #1: If pip is not recognized, you'll have to install Python (pip is Python's package manager). If Python is installed, replace "pip" by its full path.

re #2: Bots can play rated games against humans which affects both of their ratings and therefore there are restrictions on what you can do:

* You cannot run a weak bot first and then switch to a 2500+ bot - it's like sandbagging, but the BOT equivalent. What Toadofsky said about variants is true though, because the ratings are separate.
* You cannot use an engine against a BOT (in rated games). Cheating against a BOT is like cheating against a human in a way: you gain rating (in an unfair way) and the BOT loses rating. Just like cheating against humans, this is reportable and offenders will get the engine mark as usual.

@Toadofsky, ok, I see, thank you!

@ProgramFOX, thank you!

@Chesstroll_Ingot
Hello! There are many open source engine:
http://www.computerchess.org.uk/ccrl/404FRC/rating_list_pure_free.html
I am curious, which one do you plan to run?

@RMario, hello! I think to run LeelaZero. And also I coded my own bot (in AutoHotKey) for ultrabullet, which plays around 2000 level.

@Chesstroll_Ingot
A chess engine configured to 2000 Elo strength would be great for hobby players like me. No fun playing against an invincible opponent. :)

I managed it; you need to install Python. It's relatively painless for UCI engines, but XBoard engines (like Dorpsgek) require quite a bit of fiddling about.

Maybe I'll add my changes to the example client.