Eufy dual cam battery doorbell in situ charging. T8213

I have the dual cam battery doorbell.
I am wanting to be able to charge it in place by either running power supply wires to the 2 terminals at the rear or running a micro usb through the base bracket back to a charger inside.

Will either of these options work?

If USB connected, will the camera still operate whilst charging?
I am considering to set up a controlled plug pack to give it an hours charge once a fortnight.

Are the terminals at the back active for charging the battery?
What voltage, ac or dc and current capacity would be needed if this was possible?

Found this on their support / help page.

If you go the USB route I don’t know if the doorbell will still operate while charging. (Mine does but I don’t have that model).

I would not charge it constantly every night via usb, you want the battery to cycle_ to discharge & charge to maintain battery life. When it like 10% begin to charge when it reaches 85-95% cease charging.
You would just need a standard phone charger that puts out 5 volts 1000mA /1amp or higher.