Fisrt, welcome to the forums
During the session it's good to move the coal around the bowl, whatever kind of bowl that is. That ensures that the shisha is heated more evenly and produces a smoother smoke. If you leave the coal on one spot, the shisha under it will burn and you ''l have the burned taste wherever you place the coal later on.
I've never used 3kings coals (although i used other brands of 33mm's) i dont know how much heat these produce. My advice still applies with every kind of coal, especially with naturals