RB951G-2HnD ext antenna

Hello i have this routerboard and i want to install external antenna but i dont know which pigtail to choose.I have attached a photo with the routerboard onboard connectors.
Has anyone installed antenna to this routerboard RB951G-2HnD?
I also see 2 connectors ch0 and ch1 which one do i choose?
I have seen a pigtail like this Sma female to CRC9 male pigtail 15cm is this the right one?
mikrotik.jpg

The 951G does not support external antennas.

so the two connectors are only for factory use?

Yep

If we find the right connector for this plug is it possible to get rf signal from these 2 plugs?

That is not ufl and you will not find a pigtail for it. You can unsolder the antennas and solder the pigtails.