KeyAuth is an "authentication" service designed as a sort of "license key" based system. You can create keys, track what HWID is tracked to which key, and way way more.
Note
Because of how this bot works, you cannot track what HWID uses a specific key. They will all go back to the same HWID (that is, the one that is hosting the bot itself)
To disable requiring a valid HWID (in the event you change VPS providers), you can go to your app's settings in KeyAuth and set "HWID Lock" to "Disabled".
(if you are not using this bot, HWID locking should still work)
This bot takes advantage of KeyAuth's API in order to authenticate a given KeyAuth license using a Discord bot. The bot integrates nicely with Discord, using Discord's slash commands feature, so it creates a very nice UX for the user. It also has its security benefits, such as automatically doing input validation (provided you use their options field, which this bot uses).
There are many useful advantages to using a dedicated key service rather than making your own, such as easy management.
You could use this bot, for example, to "sell" access to a Discord server (sell access on Sellix -> use KeyAuth's API to generate a key for the customer upon buying from Sellix (this is officially supported by them if you have the required paid plan) -> customer gets key from Sellix -> uses it with this bot -> access!).
But generally speaking, anything! The sky is the limit :) In regards to the license, this uses GPL 3.0. In essence, you can do whatever you'd like, but you must make any modifications to the code (excluding changes in tokens/authentication keys) open-source aswell.
Caution
This is not legal advice! I'm not a lawyer. Please check the license for yourself to get a detailed understanding of what you may and may not do with regards to this source code.