I never saw any GI sales here. Is this some sort of exclusive program, or do I have to opt in for that?
Or are those sales included in the normal pp sales?

GI is exclusive only, and only certain images.
There is also Getty360 (I think also called GettyPlus?) which all files are in, which only a few buyers (reportedly) have access to, but they don't get super many sales. I think I've had only two or three. They can be good value sales, or very low value.
G360 is shown on your charts as mossy green, same as PP. However, the value will almost certainly be different.