White powder on leaves

Hi. that white powder started to appear on the leaves. what could it be? thank you!

Wpm
Humidity high?
Im no expert in mold, idk what to tell you
Someone should chime in or just search "wpm on cannabis plants"
Gl

I’m dealing with this right now in my outdoor grow, although yours looks different. I just bought some potassium bicarbonate on amazon coming tomorrow. I read a foliar spray recipe online for an ounce of potassium bicarbonate in a gallon of water together along with 1.5 cups of skim milk.

Thank you guys. My humidity is a little bit high. Looks like white powdery mildew. I will try some method to stop.