I see edema which is typically from over watering. I would recommend removing the diseased leaves and cutting back on water. Peppers prefer to be a little on the dry side from time to time. Also, I'm not sure of your climate, but the northern hemisphere is entering winter and peppers do not thrive in winter.
– user1469762Nov 30 '20 at 18:52
@user1469762: peppers survives winter in northern hemisphere, Just try it (just move on a sheltered place, or cover the plants. Do no worry if they lose all leaves, they will growth back (and still in winter, it is just initial shock).
– Giacomo CatenazziDec 02 '20 at 11:05