i know that there are many threads on this topic but i can't fully understand or find information about level three and four.

i can't attend any retreats as i am in Egypt.
and i want to advance my training to get level 3 and four.
i found that there are meditations for level three and four but anyone say that you have to attend.

i want to know if there any possibility to get level 3 and 4 by practicing the meditations these levels?

what is the prerequsites to practice the meditations for these levels?

and thanks a lot for your great help and support.