Did it work in your server? I added this to my shop too, but while testing and selling the element, the shop says that I don't have element in my inventory even when I have much more than the required amount. This also happens when adding black pearls, the plugin seems to have an...
The vendor where I host my cluster helped me installing MySQL on one of my servers, then I changed the configuration file of each map to point that MySQL DB, that's how I solved this. Wanted to share this here, other people with the same issue may find it useful.
I want to use the same DB for all the server in my cluster, every server has different IP addresses because this is how it works where I'm hosting my servers. I wonder if there is a guide to setup the MySQL DB that you could share.
My SQL DB section looks something like this in the config...