How do I use Fish's Alt bindings using Kitty on macOS

I acquired a macOS machine for the first time, and I can't figure out how to use commands such as alt+E to open the current command in $EDITOR.

I don't want to remap the ⌘ key to alt system-wide, but I can't figure out how to the remap in either Kitty or Fish.

Why is the fish binding not working in mac os? is a relevant question but the answer there only applies to iTerm2.