How to Remove Branding Plugin History setting After Deactivating the Plugin?


I have been trying to setup a custom admin message for my multisite network using Branding plugin. I have been advised to enter some custom code in the "Admin message box" of the branding plugin.

But the problem is: The custom code i have entered has messed up the whole wordpress backend, i tried fixing the problem by deactivating & reinstalling the plugin. But as soon as the plugin is activated everything disappear including the setting for the plugin itself. (attached photo)

My Question now is: How can I completely delete the Branding plugin history so that it is just like installing it for the first time?

I have an earlier request here:

But I have Not Received a reply for 7 days, and i was disappointed.
That's why i opened this request.

Looking forward your reply.