Wheels are very expensive and a wheel repair is expensive, too. You will need in the first place any rim of the same nominal diameter (622 mm for a 700c wheel) with the same number of spoke holes and a similar internal rim width. (An example: if the internal width of your original rim was 27 mm but you cannot find a rim in that size, a 25 mm rim would do). The spokes might be re-used or not. The rear hub can be certainly re-used. Then you need to order the wheel rebuild at a shop. (The LBS person might tell you that you needed new spokes, and that's not free either).
Is the rear wheel useless after being dented? Nowadays, e-bikes have a low resale value. If you spend a lot of money for the wheel repair, you might actually end up with a loss. Perhaps it is better to keep the C380 as a guest e-bike?