as per info on the web the oil drain interval is quite high. I havent come across a single figure but some say its 60,000 miles, others say its 100,000 miles (covert it into Kms then see how big the interval is). But its always good to have it changed sooner.
The oil as per what i ve read is "Toyota ATW WS" (which is supposed to look red in colour unlike CVT oils)
Whenever you get it changed then share your experience. also let us know if theres any transmission oil filter that can be changed.