Mapping a "Command" key in neovim / alacritty

Question

I am failing to map Command+t, Command+[ and Command+] keys in neovim under macOS / Alacritty.

I've reduced my neovim/Alacritty to be minimal. Both configs in their entirety can be seen on the screenshot:

My thinking process for assigning the chars in alacrity was this:

1. I went to nvim,

2. entered the following command,

   echo "\<D-t>"
   

3. got an output:

   <80><fc><80>t
   

4. used the output to add a binding in Alacritty:

   - { key: T, mods: Command, chars: "\x80\xfc\x80t" }
   

What am I doing wrong?