I have seen your posts. You had posted under a blog post, and that requires approval on my part the first time you post. Since your question was about requesting support you were correct to post it here on the forum. I will delete your identical post on the blog comments. You are also welcome to email me if you prefer.
I am not sure I understand your question about purchasing extensions. If you wish, you can buy a subscription to gain access to some extensions to the plugin as described on the homepage.
The plugin can be linked to the coin adapters that are provided, unless if you develop your own. You cannot use fiat at this time.
Hope this answers your questions. Do let me know if you need anything else.