Multi projectors with Mac

Hi everyone,

I have Millumin both on my laptop and on a MacMini.

It's not so clear how can I have differents projectors connected with differents canvas.

I would need the simple way to have

canvas1 on projector 1

canvas 2 on projector 2

etc...

For the Mac Mini

1/ should I plug 2 different HDMI (via usb-c)

2/ Or should I buy an external device ? Is the Matrox Head the right thing to buy ?

Sorry for these basics questions, I'm a bit lost

Thanks