How to Hide Templateberg - Gutenberg Templates, WordPress Themes Template Kits & WordPress Templates Admin Menus

function plt_hide_templateberg_menus() {
	//Hide "Templateberg".
	remove_menu_page('templateberg');
	//Hide "Templateberg → Templateberg".
	remove_submenu_page('templateberg', 'templateberg');
	//Hide "Templateberg → Gutenberg Templates".
	remove_submenu_page('templateberg', 'templateberg-gutenberg-templates');
	//Hide "Templateberg → Themes Template Kits".
	remove_submenu_page('templateberg', 'templateberg-themes-template-kits');
}

add_action('admin_menu', 'plt_hide_templateberg_menus', 100);

Where do I put this code?