GL-AR300M16-EXT which connector for directional Antenna in WISP Mode?

i’m trying to connect the router to a wireless Network in WISP Mode. I would expect that one Antenne is used to connect to the external Network and the other is used to provide the local Network.
I would like to use a directional antenna to connect to the Wireless Network but how do i know on which connector i should attach the directional antenna?

Both the router works the same, i.e. you cannot separately them for different purpose.

So if you want to connect a directional antenna, you can just connect to any SMA port and try.