Which Part of a Brushless Motor Needs to be Sealed?

Hi

We’re working on a very small impeller (2.5 cm diameter), and the driving motor we’re using is a drone motor as we need the housing to be as compact as possible, Emax motor, provided in the link
https://skynexdrones.com/brushless-drone-motor-emax-mt2213-935kv-x4/

The motor does not have an en embedded encoder or anything, it’s just stator and rotor.
In order not to get the motor burnt out or short-circuited by the water into failure, what parts exactly of a brushless motor, or in this case a drone brushless motor, that should not touch water???

Some say it’s the whole winding, others say that it’s only the connections, and we also found people telling us that the whole motor can work just fine without chemical seal…

Please help us out if you know anything about this, I have worked with the T-100 and found that it has chemical seals, but it’s not so easy to figure out which parts are important to seal.