Package with Maven then deploy to the plugins folder of your Neo4j v4.x server.
The deploy script will copy the jar from a mvn clean package. Create a .env file. Use your path to your local Neo4j:
PLUGINS="/Users/michael_marshall/Library/Application Support/com.Neo4j.Relate/Data/dbmss/dbms-ec04a7d5-bfb8-4549-bceb-772f6b58bd08/plugins"