This is a very relative question. As it depends on the weight of the rider, gear, steepness of the hill, etc.,
In steep hills, riders with hub motors are most likely going to need to constantly pedal.
However, in mid-drive motor models, this needs isn’t as much as the hub motor version.
We do not recommend our riders to ride uphill just with the throttle. This might create irreversible damages on your motor and controller, which are expensive parts to replace.