How to Hide Pixel Cat Lite Admin Menus

function plt_hide_facebook_conversion_pixel_menus() {
	//Hide the "Pixel Cat" menu.
	remove_menu_page('fca_pc_settings_page');
	//Hide the "Pixel Cat → Pixel Cat" menu.
	remove_submenu_page('fca_pc_settings_page', 'fca_pc_settings_page');
	//Hide the "Pixel Cat → Upgrade to Premium" menu.
	remove_submenu_page('fca_pc_settings_page', 'pixel-cat-upgrade');
}

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

Where do I put this code?