How to Hide Kipphard Accessibility Audit Admin Menus

function plt_hide_kipphard_accessibility_audit_menus() {
	//Hide "Accessibility".
	remove_menu_page('barrierefrei-check');
	//Hide "Accessibility → Dashboard".
	remove_submenu_page('barrierefrei-check', 'barrierefrei-check');
	//Hide "Accessibility → Statement".
	remove_submenu_page('barrierefrei-check', 'barrierefrei-check-statement');
	//Hide "Accessibility → Settings".
	remove_submenu_page('barrierefrei-check', 'barrierefrei-check-settings');
}

add_action('admin_menu', 'plt_hide_kipphard_accessibility_audit_menus', 11);

Where do I put this code?