More likely that's the motor controller. But I am not familiar with that bike. It's possible that a charger did connect to the controller. It just depends on how they wired the bike.
This can be a problem when reviving a dead old production ebike. You can't get original parts, so what you can get won't work so well because they seem to always wire the production bikes different from kits.
Both times I resurrected an old brushed motor bike, I ended up ripping out everything on the bike except the brushed motor. Then built from scratch using scooter parts to put a controller and throttle back on it.
Just too much trouble to get everything working again, lights, horns, locks, etc.
