This is an example Repository for a generic Slimefun4 Addon. In the top left is a button "Use this template", click this to create your own Addon for Slimefun4 using this basic template.
Naivagte to src/main/java
and rename the package and the .java File to your liking.
Suggestion: "me.(Your name).(Your Project's name)" (all lower case) and "ProjectName.java"
Navigate to src/main/resources/plugin.yml
and change the "author" and "main" attributes.
You may also want to change the description to something meaningful.
Navigate to pom.xml
and change the group id to "me.(Your name)" and change the arficact id to the name of your Project.