[How to use mechanical shutter in XA5]

Hello i just bought universal flash yongnuo yn560 III and trigger PT 04NE for my XA5 camera, but i cant use at all.

I already searching on google the problem was i must change to mechanical shutter

I was open fujifilm website , there is setting for shutter type in camera, but i cant found in my XA5 camera

My question :

1. How to use Mechanical shutter in XA5

2. Why i cant use my universal flash

 

thanks in advanced