Hmm I've seen while browsing on sites that you can't check the tranny fluid bcuz of the fact that there isn't a dipstick & that you gotta take it to a shop to get it checked out since it'* gotta be lifted up to do so. But I'm not for sure if that'* true or not, maybe someone else on here knows more about it
There is usually a fill plug on the side of the transmission that the service tech pulls out and checks the fluid level and fills to the appropriate level.
The transmission is a sealed unit and requires no maintenance for 100,000 miles.
So as long as it is not leaking - you don't mess with it.
One reason why there is no dip stick is because you cannot use the old Dextron transmission fluid in it.
It probably uses a synthetic fluid.