Horizontal movement for FOF

I'm trying to make an FOF that moves horizontally, but all the linedefs that move FOFs seem to only work vertically. I've been looking for all kinds of FOF movement linedefs but I can't find any that moves horizontally. Does somebody know what linedef it is, or if basically horizontal FOF movement isn't a thing in SRB2 yet?

The only things that move horizontally are polyobjects. They can be pretty hard to master, so I suggest you try looking at this polyobject tutorial on the srb2 wiki. https://wiki.srb2.org/wiki/PolyObject_tutorial