Function __fui_debug_key_event 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn __fui_debug_key_event(
    event_type: u32,
    key_ptr: *const u8,
    key_len: u32,
    modifiers: u32,
)

Safety

key_ptr must be null for an empty key or point to key_len readable bytes.