How to Hide Mailercloud - Integrate webforms and synchronize website contacts Admin Menus

function plt_hide_mailercloud_integrate_webforms_synchronize_contacts_menus() {
	//Hide "MailerCloud".
	remove_menu_page('mailercloud-settings-page');
	//Hide "MailerCloud → Settings".
	remove_submenu_page('mailercloud-settings-page', 'mailercloud-settings-page');
	//Hide "MailerCloud → Contact Sync".
	remove_submenu_page('mailercloud-settings-page', 'mailercloud-subscriber-synchronisation');
	//Hide "MailerCloud → Forms".
	remove_submenu_page('mailercloud-settings-page', 'mailercloud-signup-form-listing');
}

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

Where do I put this code?