function plt_hide_gutenberg_menus() {
//Hide the "Appearance → Fonts" menu.
remove_submenu_page('themes.php', 'font-library-wp-admin');
//Hide the "Settings → Connectors" menu.
remove_submenu_page('options-general.php', 'options-connectors-wp-admin');
//Hide the "Settings → Gutenberg" menu.
remove_submenu_page('options-general.php', 'experiments-wp-admin');
}
add_action('admin_menu', 'plt_hide_gutenberg_menus', 101);