They are carmen sweet peppers and out of the sun peppers have very smooth surface with no wrinkles. They turn red when ripe.

That is the beginning of sun scald. I just found one of mine that looks like yours. I had some that I picked earlier that were so badly sunburned the area scalded turned brown/dead. We had some days in the 90+ range and those peppers were south facing. I pulled out the shade cloth to cover that side of the row when I realized what was happening.

I grow "Carmen". Excellent sweet pepper variety.

I'd pick them before they get any worse and use for cooking

As carolb_w_fl_coastal_9/10 said, they do get worse. I picked two of mine yesterday and one has the beginning of a spot that will be bad. That brown spot is hard to see with the reflection but it a sunburned area.

King of the North peppers

Thanks! I was pretty sure, only the ones with full sun made it obvious! Most are fine so Igot lucky.