I'm not very technologically advanced, nor do I remember well what I do know about making pico-8 carts, but can't you export to any platform you want, and if you can't, can't you just get the plain cartridge?
Viewing post in Image-To-Pico8 Converter ImgToP8 comments
When you create something on Pico-8, yes, you can export as ".p8" cartridge, or export to Windows/Linux/Mac executable, or even to a HTML5 page playable in browser.
However Image-To-Pico8 Converter is not a Pico-8 cartridge. It's written in C++/Allegro (and not in Lua) and it can be run only on Windows.
So no, i can't.