Undefined index: enable

When you work on Debug mode, there is a ton of warns like this:
Undefined index: enable n /…/wp-content/plugins/social-sharing-toolkit/social_sharing_toolkit.php on line 616 and on line 659 on the public side, and on lines 412 and 616 in the Dashboard.

Please, it should be a simple declaration and will make developers life easier.

Thanks in advance.

https://www.ads-software.com/extend/plugins/social-sharing-toolkit/