Function bevy_ui_navigation::systems::default_keyboard_input

pub fn default_keyboard_input(
    has_focused: Query<'_, '_, (), With<Focused>>, 
    keyboard: Res<'_, Input<KeyCode>>, 
    input_mapping: Res<'_, InputMapping>, 
    nav_cmds: EventWriter<'_, '_, NavRequest>
)

A system to send keyboard control events to the focus system

supports WASD and arrow keys for the directions, E, Q and Tab for scopped menus, Backspace and Enter for cancel and selection

The button mapping may be controlled through the InputMapping resource. You may however need to customize the behavior of this system (typically when integrating in the game) in this case, you should write your own system that sends NavRequest events