Risk/reward tool

FTMO Trader Scouting
Where do you guys backtest?
You may try Forex Tester, Trading View etc. Here is a thing you do back testing to find out how it performed in the past. If it produces good result, you must practice on demo before implementing on your live account. Do not start using a strategy on a live account straight after backtesting.
I found a good video on Youtube once which explained back testing once and how to do it, but I can't find it now
FTMO Trader Scouting