There is a cover that goes on the bottom (it bolts to the frame rail) and covers the crank pulley.
Part numbers I see are YS4Z-6775-DA or YS4Z-6775-GA, but I can't find them anywhere. Your best bet may be a junkyard, if the part is still on there. Most get taken off/ripped off and never put back on.
X2, most in the junkyards aare missing or broken, the belt snaps and they break up easy once the plastic gets old and brittle.
You don't need one at all unless you drive through large amounts of rain or snow. been driving three of the cars for years with them gone and zero issues here in Texas. Just remember that a lot of water hitting belt can make the power steering not work for a couple seconds, but it typically takes enough water you need to be going slow and aware already.
If your belt slips too much with it gone that may be telling you you need a new belt.