ungrab_key(+Key, +ModifiersMask, +UngrabWindow)

Releases the passive grab started by the key combination on the specified window if it was grabbed by this client. Has no effect on an active grab.

Key is the key that should be ungrabbed. One of:

An integer
Giving the keycode.
A valid key name
As given by keysym/2.

ModifiersMask is one of:

An integer
A bitmask giving the state of the modifier masks. The predicate modifiers_mask/2 is useful to translate between modifier specifications and bitmasks.

UngrabWindow is the ProXL window where the grab is in effect.