^ in ZSH (and many other softwares; see for example
stty -a) refers to control key e.g. for control-L to clear the screen one might find in the ZSH keybindings list
% bindkey | grep clear
I cannot comment on how
^@j in the ttscoff keybindings relate to ZSH. That software appears unrelated to ZSH; the full list of what ZSH recognizes can be found in the
zshzle(1) manual, which for some version of ZSH (do instead check the manual for the version you have and do not blindly assume that this list is correct for that version of ZSH) includes
\a bell character
\e, \E escape
\f form feed
\n linefeed (newline)
\r carriage return
\t horizontal tab
\v vertical tab
\NNN character code in octal
\xNN character code in hexadecimal
\uNNNN unicode character code in hexadecimal
unicode character code in hexadecimal
\M[-]X character with meta bit set
\C[-]X control character
^X control character
To make the Apple command key generate codes in the terminal requires that the terminal program be configured to do so; the instructions for this will vary depending on whether you are using
iTerm.app or something else (dig around in the preferences or check the manual).
iTerm.app (this may change; GUI apps tend to move things around over time) try the iTerm2 menu, Preferences, Keys, find the widget to add something, and then "send hex code"
Then in ZSH
bindkey this sequence
00000000: 020a ..
% screencapture -s hexcode.png
% bindkey '^B' clear-screen
and now splat-shift-option-O should cause ZSH to clear the screen; instead
bindkey your desired widget and set that in your configuration:
bindkey '^B' autosuggest-accept-suggested-small-word
or whatever other binding that works for you. Be sure to run
bindkey and inspect that no other existing widget that you want to use uses the key code...