On macOS option-u doesn't trigger entering of umlauts

[adaitche]

macOS has the following feature and it doesn't seem to work in Ghostty.

To enter German umlauts, e.g. ü, one can press option-u followed by the Latin letter to add the umlaut to. For example, option-u followed by a would result in ä. This works across various apps on macOS, including various terminal emulators (iTerm, Alacritty, macOS Terminal).

In Ghostty however option-u seems to yield Esc, at least for me. Unbinding it via --keybind='alt+u=unbind' doesn't change the behaviour.

[adaitche]

Turns out it was already answered here