To be honest, there are many shortcomings. Not only was the last lecture update in 2018, but the lecture was not filmed separately for online lectures, but it felt like it was uploaded as it was from a recording of a class somewhere, and even non-lecture content was included. (I wonder if you could have edited and uploaded this part) Compared to other lectures, the price is a bit expensive for the short time, and since it is old content, as someone else commented, you have to look at the official documents and develop it separately.