upsell function ftp error

getting this error

Fatal error: Uncaught Error: ftp_nlist(): Argument #1 ($ftp) must be of type resource, null given
in /wp-admin/includes/class-wp-filesystem-ftpext.php on line 438

Call stack:

1. ftp_nlist()
   wp-admin/includes/class-wp-filesystem-ftpext.php:438
2. WP_Filesystem_FTPext::exists()
   wp-content/plugins/ultimate-blocks/includes/pro_manager/base/Pro_Extension_Upsell.php:143
3. Ultimate_Blocks\i\p\b\Pro_Extension_Upsell::generate_upsell_data()
4. call_user_func_array()
   wp-content/plugins/ultimate-blocks/includes/pro_manager/base/Pro_Extension_Upsell.php:82
5. Ultimate_Blocks\i\p\b\Pro_Extension_Upsell::get_upsell_data()
   wp-content/plugins/ultimate-blocks/includes/pro_manager/Pro_Manager.php:164
6. Ultimate_Blocks\i\p\Pro_Manager::prepare_priority_upsell_data()
   wp-content/plugins/ultimate-blocks/includes/pro_manager/Pro_Manager.php:44
7. Ultimate_Blocks\i\p\Pro_Manager::init_process()
   wp-content/plugins/ultimate-blocks/includes/common/traits/Manager_Base_Trait.php:53
8. Ultimate_Blocks\i\p\Pro_Manager::init()
   wp-content/plugins/ultimate-blocks/includes/class-ultimate-blocks.php:180
9. Ultimate_Blocks::define_admin_hooks()
   wp-content/plugins/ultimate-blocks/includes/class-ultimate-blocks.php:64
10. Ultimate_Blocks::__construct()
    wp-content/plugins/ultimate-blocks/ultimate-blocks.php:127
11. run_ultimate_blocks()
    wp-includes/class-wp-hook.php:310
12. WP_Hook::apply_filters()
    wp-includes/class-wp-hook.php:334
13. WP_Hook::do_action()
    wp-includes/plugin.php:517
14. do_action()
    wp-settings.php:495
15. require_once()
    wp-config.php:94
16. require_once()
    wp-load.php:50
17. require_once()
    wp-admin/admin.php:34
18. require_once()
    wp-admin/plugins.php:10

by inserting the following I was able to dodge the error on WP6.3 with Ultimate Blocks Version 3.0.1 inside ultimate-blocks/includes/pro_manager/Pro_manager.php circa line 156.

/**
* Prepare upsell related extension data.
* @return array upsell data
*/
private function prepare_priority_upsell_data() {
// hotfix aug 12
return [
‘upsellExtensionData’ => []
];