How to add canvas spine plugin to game?

Hi,
Just checked out phaser3-project-template, and tried to add SpineCanvasPlugin but to no avail.
I did exactly as the example, then npm start, but I got the ‘this.load.spine is undefined’ error.

Can anyone please shed some light on this?
Because right now phaser seems hard to use with so little documentation. It’s good news that spine animation got a nice update, but then how to get it work?

Thanks!