In a QGIS project, I have several raster layers---satellite imagery for specific areas--and I wish to serve these via QGIS Server. WMS works nicely, and they show up for WCS. But I cannot see the layers in WFS, which is required. Nor do they show up as FeatureTypes in GetCapabailities, nor can I see them in the configuration for the project (1st screen capture). The layer properties are also set, as I expect they'd need (2nd image).
What am I missing?