Brian Hi Brian, thank you for using Buttonizer and your feedback! That's a good point!
At the moment we do not yet support some kind of user roles for user groups to manage Buttonizer. But I do like the idea to add that in the future. Do you use a plugin for managing user permissions for a plugin, or is what you meant build in into WooCommerce?
bad request doesn't sound an error that comes from WordPress, that should be something like
not enough permissions or something like that and may comes from your webserver. Unless you use another WordPress plugin that keeps an eye on permissions (or some kind of security plugin).
If you go to the console, are you able to check the URL that gives the error?
Let me know! 🙂