Using M1 MR1100 with an external antenna

Hello,

I have several questions regarding the M1 MR1100 used with an external antenna, probably an Poynting one  :

1. Can the M1 be used with such an external antenna while charging using the USB Type-C cable plugged to an USB charger ? I've seen that some other routers need to be plugged to 220V when using such an external antenna and I don't want to have to use the AC/DC 220V adaptor, but only the USB charging.

2. Should I use a 4X4 external antenna, or a 2x2 one ? If both 4x4 or 2x2 antennas can be used, what would be the differences between having a 2x2 or a 4x4 antenna ?

3. Are there some technical requirements for an antenna to be compatible and to work fine with the M1 ? I guess thre are some requirements but I don't know which ones  ...

It's for using it in my campervan with an external antenna on the roof. That's why I want to use it without needing AC powering.

Thanks a lot !