Slitherine

Tried my first Hussite army in their campaign and first game it says I have 4 field fortifications to deploy. I couldn't find them anywhere even mousing over the woods at the map edge. Where do you find these things? I tried different keys and no luck.
Thanks in advance

You get one field fortification (FF) section per non-light infantry or artillery unit plus a couple extra.

To place them, click on one of the infantry units and move the cursor in the direction you want to place the FF section and a shovel icon will appear. You can also remove a section if you want to change its location.

Once you leave the deployment phase, they're fixed.

[Edit] Units on slopes can't place FF.

Thank you for your help