Can’t activate Plugin in WP 6.0

It shows the error message:

Fatal error: Uncaught Error: Undefined constant "label1" in /home/.sites/8/site9649241/web/wp-content/plugins/label-plugins/lp_admin_page.php:23 Stack trace: #0 /home/.sites/8/site9649241/web/wp-includes/class-wp-hook.php(307): initial_plugin_labels('') #1 /home/.sites/8/site9649241/web/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array) #2 /home/.sites/8/site9649241/web/wp-includes/plugin.php(476): WP_Hook->do_action(Array) #3 /home/.sites/8/site9649241/web/wp-admin/plugins.php(194): do_action('activate_label-...') #4 {main} thrown in /home/.sites/8/site9649241/web/wp-content/plugins/label-plugins/lp_admin_page.php on line 23