outfly/src/main.rs

use bevy::prelude::*;

fn main() {
    App::new()
        .add_systems(Update, handle_input)
        .add_plugins((DefaultPlugins, ))
        .run();
}

fn handle_input(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut app_exit_events: ResMut<Events<bevy::app::AppExit>>
) {
    if keyboard_input.pressed(KeyCode::KeyQ) {
        app_exit_events.send(bevy::app::AppExit);
    }
}