Don't know the details, but apparently "[it's] not designed to run PICO-8 carts out of the box". PICO-8 has a really low resolution, lower than a Game Boy, which makes it a bit difficult to write code in.
That would be really cool and a fitting level of meta if the Picotron could be used to develop PICO-8 games. I guess you could bolt a PICO-8 onto the side of the Picotron like one of those 90s console devkits.