Configuring IDE 2.0.0 beta7 for JLink debugging

I have search but cannot find any information that works about how to set up the IDE 2.0 for debugging using a JLink, I have a JLink-Ultra. If I launch the UI-based JLinkGDBServer it can connect to both the H& and the H4. However, in spite of creating a debug_custom.json file (see below), when I press the start debug button all that happens is a new file named launch.json opens in the IDE.

Hopefully someone has the IDE 2.0 working with JLink and JLinkGDBServer.