Most current ebike models by Rad Power Bikes have mounting points for a standard water bottle cage. The RadRover, RadCity 16", RadCity 19", and RadWagon models have water bottle cage mounting points located on the underside of the downtube, circled below.
The RadMini Step-Thru and the RadCity Step-Thru have mounts for a standard water bottle on the rider-side of the downtube, circled below.
The RadMini does not have mounting points for water bottle cages.
The installation of third-party accessories or accessories from Rad Power Bikes not explicitly recommended for your bike model, is at your own risk. Using aftermarket accessories or components that have not been tested by Rad Power Bikes for safety and compatibility may void your warranty, create an unsafe riding condition, damage your bike by Rad Power Bikes, or result in serious injury and/or death.