LoginSecurity: https://www.spigotmc.org/resources/loginsecurity.19362/
LoginSecurity is a simple, light, fast and secure user authentication management system first created in 2012. It's core focus is to be simple to setup up and use.
Version hosted in TeTeOS.Net: [You can download with wget] Link: https://www.teteos.net/files/minecraft/plugins/LoginSecurity-3.1.jar Plugin version: 3.1 Tested MC versions: 1.8 - 1.17
If your server version is 1.17 or highter, you can try newer alternative: NexAuth : https://www.teteos.net/d/267-minecraft-plugin-nexauth-java