Premium Resource Website API

Hello, I'm Bob.
I'm relatively new around here, so please treat me well and feel free to correct me should you feel the need to criticize something I've said.

I have a web API for a resource I wish to make premium someday, but I'd like to be able to require a user to enter their ID into my website after having bought my plugin in order to generate an API key. What this would allow is for me to bind said key to their account (my plugin's core functions are stored in the RESTful API server, to prevent piracy). I could log the IPs used for each key and further monitor their use.
The issue I'm facing is that I need a way to check that a user, from their spigot user id, has bought my plugin. I need to do this autonomously, or there will be discord and uprising should I ever decide to go on vacation. I see this as simple as creating a key on the spigot site and using it when requesting sensitive information such as this. Is this possible, or in the works? How else would I go about it (can't login as bot if two-factor is enabled - compulsory)?

Thanks :3
~ Bob

 

I completely missed that (as you do).
That's a real bummer. I suppose safety is a factor in that decision, though it still is something of a sacrifice.

Thanks anyhow.