This is an addon for securegrid and does not function as a standalone plugin,
As of version 1.0.4, compiled on Java 8, support for Java 11 is retained.

to Install, download the ZIP, decompress it, move the JAR file into ~/plugins/Securegrid/Addons

and restart your spigot server

Requires authy-java and Securegrid API to compile from source, authy-java has to be shaded into the final jar