I already had LPrint running on a Raspberry Pi 3A, supporting a Seiko label printer for my home network. This printer did not support white text, so I bought a Phomemo P12 that did.
I do not have a smartphone, and it seemed that I needed one to use it at all. I am rather elderly and possibly the world's worst programmer, with limited vision, so I asked ChatGPT whether I could drive this printer using LPrint.
After a few days of to-ing and fro-ing, we came up with the files presented...