How to Hide Pixelavo - Facebook Pixel Conversion API (CAPI) / Server Side Tracking Admin Menus

function plt_hide_pixelavo_menus() {
	//Hide "Pixelavo".
	remove_menu_page('pixelavo');
	//Hide "Pixelavo → Pixels".
	remove_submenu_page('pixelavo', 'admin.php?page=pixelavo#/pixels');
	//Hide "Pixelavo → Custom Events".
	remove_submenu_page('pixelavo', 'admin.php?page=pixelavo#/custom_events');
	//Hide "Pixelavo → Settings".
	remove_submenu_page('pixelavo', 'admin.php?page=pixelavo#/settings');
	//Hide "Pixelavo → Upgrade to Pro".
	remove_submenu_page('pixelavo', 'https://hasthemes.com/plugins/facebook-pixel-wordpress-plugin/?utm_source=admin&utm_medium=mainmenu&utm_campaign=free#pricing');
}

add_action('admin_menu', 'plt_hide_pixelavo_menus', 221);

Where do I put this code?