Thank you for your question and pictures. It appears your pepper plants have been affected with bacterial leaf spot, a common pathogen which affects tomatoes and peppers. It is very contagious and is spread from plants to plant very easily. I see you have your peppers adequately spaced which is good, but unfortunately you may have to discard your infected plants. The wet spring and high temperatures most of Minnesota experienced also contributes to this bacterium, as we are seeing it in tomato plants also. It's difficult for me to see the peppers which are growing from the pictures, but this publication from Extension should explain what bacterial leaf spot is and how to treat it:

Bacterial spot of tomato and pepper | UMN Extension

This fact sheet from the West Virginia University is also very helpful:

Bacterial Leaf Spot of Pepper | Extension | West Virginia University (wvu.edu)

I wish I had better news for you, so I hope you can recover a few of your pepper plants. Be sure to sterilize your gardening tools as you move from plant to plant to avoid spreading the bacteria.