How to Hide CouponAPI Admin Menus

function plt_hide_couponapi_menus() {
	//Hide "Coupon API".
	remove_menu_page('couponapi');
	//Hide "Coupon API → Settings".
	remove_submenu_page('couponapi', 'couponapi');
	//Hide "Coupon API → BrandLogos.org".
	remove_submenu_page('couponapi', 'couponapi-brandlogos-settings');
	//Hide "Coupon API → CSV Upload".
	remove_submenu_page('couponapi', 'couponapi-file-upload');
	//Hide "Coupon API → Logs".
	remove_submenu_page('couponapi', 'couponapi-logs');
	//Hide "Coupon API → Troubleshoot".
	remove_submenu_page('couponapi', 'couponapi-troubleshoot');
	//Hide "Coupon API → Coupon Custom Template".
	remove_submenu_page('couponapi', 'couponapi-custom-template');
}

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

Where do I put this code?