I found the way to use vsc vim extension in Arduino IDE 2.x

Development Tools IDE 2.x
2

Thank you very much!

That's exactly what I need. Unfortunately, I can't follow your steps with success. I use Arduino IDE 2.2.1. My configuration directories don't look like yours. Here's what I have:

VScodium v1.84.2:

~/.vscode-oss/extensions> ls
...
extensions.json
...
oderwat.indent-rainbow-8.3.1-universal
...
vscodevim.vim-1.27.1-universal

To Arduino IDE 2.2.1, copy (Note: the path is different, as suggested here):

~/.arduinoIDE/extensions> ls
oderwat.indent-rainbow-8.3.1-universal  vscodevim.vim-1.27.1-universal

After starting Arduino IDE, the Rainbow starts right away; the Vim plugin starts too, but with an error:

Activating extension 'Vim' failed: Cannot add property 0, object is not extensible

What do I have to correct? Note that I skipped step 4 (not needed any more?)