How do i setup 40G qsfp+ port on CRS326

I am about to use the first qsfp+ 40G port on my CRS326 switch for my truenas server

i noticed in the winbox dashboard it is showing as 4 x sfp+ ports but i only want to configure this as a single 40G port wiht my 40G DAC cable so how do i set this up???
mikrotik-40g.JPG