Capsicum annuum L. specifically Akamu, Kaiki, Kalani, Kaolin e Moke from Isla® seeds. Reference: https://www.mdpi.com/2311-7524/7/9/287

These: https://www.walmart.com/ip/Fresh-Organic-Mini-Sweet-Peppers-8-Ounce-Bag/111146370?athbdg=L1200

All sweet, no spicy. About 1/4 the volume of a regular bell pepper.

I don't have an answer but I've had success growing them from seeds saved from when I've bought them at the grocery store. This year I'm going to test out Healthy peppers, no idea how similar they'll be.

Maybe it's a gypsy pepper.

Gypsy peppers, botanically classified as Capsicum annuum, are a hybrid variety belonging to the Solanaceae or nightshade family. The peppers are also known as Cubanelle peppers, and are a hand-bred cross between a sweet pepper and a bell pepper. Gypsy peppers are a popular home garden variety in the United States, favored for their thin skin, sweet flavor, and ability to be harvested at any stage in maturity.

Source: https://specialtyproduce.com/produce/Gypsy_Bell_Peppers_13736.php

Are they talking about “sports” peppers?

Seems like these are a hybrid between a bird pepper and a bell. https://www.specialtyproduce.com/produce/Bell_Peppers_Mix_Mini_Sweet_2662.php Looks like people are growing them from the red seeds. Warning reddit link. https://www.reddit.com/r/aerogarden/comments/u5ckyr/has_anyone_grown_mini_sweet_peppers_thinking_of/

I did just come across these which look to be the same thing I buy at the grocery store: https://www.johnnyseeds.com/vegetables/peppers/sweet-peppers/lunchbox-pepper-mix-organic-snack-pepper-seed-3515G.html