Having this is not an instant thing.
Read a whole pdf, watching their videos and etc.
After that, you need to pay for a market data to have DOM, another fees again. Or register to some brokers that offered the DOM data for free (but this one is rare, except your trading volume is high, also the minimum deposits is big too).
So if you only have a small capital, this courses will only stuck inside your folders, even thought there is indicator or software that can replicate an order flow or DOM, its just an forecast, not the real one.
So that's why this product, doesn't have so much interest on peoples.