Is there a minecraft mod that transfers rank and pets to the actual players?

My sister and her friend are starting a minecraft server and they are selling ranks and pets and since I'm setting up their website and handling all of the financial stuff I was curious as to how the ranks and pets get transferred" from PayPal (where they pay for it) and their minecraft account on our server. So is there a mod for this "transferring" process or is it a manual action that one of the admin's must do themselves?

Many servers use the Enjin plugin, but that connects directly to an Enjin page, which is a sort of website builder for games, and obviously you intend to manage the website yourself. Pets and ranks are transferred generally by a command put in by an admin or above, but they can be put i directly through the server console. It would require that the website run the command. This is a server side action, and mods in minecraft are clientside, so you would need a plugin.