In order to connect to NGS with the NATS java client, you need to include a java dependency for ED25519 support, set the connection to secure, and enable the NATS credentials.
Options o = new Options.Builder().
authHandler(server("nats://connect.ngs.global:4222").
Nats.credentials("/users/colinsullivan/.nkeys/creds/synadia/First/First.creds"))
secure().