If you’re towing frequently, which is considered “heavy duty,” the schedule is every 25,000 miles.
In all parts of the world, except the USA, the scheduled service interval is every 60,000 miles (100,000 km).
There is NO REPAIR for the CVT, you have to remove a sump to check the fluid level.
If you are planning to change the fluid yourself, please familiarize yourself with the proper drain and fill bumps on the CVT model fitted to your vehicle. There are many posts on this forum about removing incorrect faults and then adding transmission fluid in the wrong place, resulting in the need for a CVT replacement. This is a very expensive exercise, about $8,000.
Sea grass