Amazon has a ton of cheap 2s lipos. However, the EC3 connector on your car isn't very popular, so you will need to change them out, or get an adapter.

Battery: https://www.amazon.com/POVWAY-5200mAh-Battery-Hardcase-Vehicles/dp/B098T5Z1HW/

Adapter: https://www.amazon.com/FLY-RC-Connector-Adapter-Adapters/dp/B078RPMHR9/

Charger: https://www.amazon.com/BosLi-Po-Battery-Charger-Interface-Charging/dp/B0B81HWY4F/