It shows me a layout named "Vim for Trebisky".
A button at the bottom says "Save to my keyboard". Below that it says "Teensy chip detected". I try the "Save to my keyboard". It tells me to use a paperclip to press the reset button, then connect -- but it doesn't seem to work.
A link says download firmware. This yields ergodox_ez_shine_vim-for-trebisky_4Jbyn_pMR5d.hex in /home/tom/Downloads and is exactly the same as a file with the same name from October of 2021.
At top right is an orange field that says "firmware v20.0" and when I hover over it, it says "this layout is based on outdated firmware, recompile to update.
To recompile, I need to go to the "My Layouts" page, select my keyboard, click Modify and make changes, then click the Compile button.