Need help with creating JARs

I’m trying to add my own OTP flow to authentication. I’ve made a simple project which creates an OTP and send it to the users mail. I’ve based my project on this video i’ve found: 2FA with Keycloak and SMS based OTP text messages | Niko Köbler (@dasniko) - YouTube
I’ve editted this project slightly with minimal changes.

Now the part comes where I have to build the JAR, put it in my Providers folder, build Keycloak and it should show up.

However this is not the case. No matter how I create the JAR, it doesn’t show up in the dropdown where I expect it. Does somebody have a tutorial or any advice on how to build a JAR for Keycloak?