How to add theia plugin while run packaged theia with node?

I develop a ide based on theia with a cpp syntax highlight plugin(it’s a vscode extension). My package.json in the root contains a script:
"start": "theia start --plugins=local-dir:../../theia-plugins", so I run the yarn start and my ide could load this plugin.
But when I packaged the entire IDE application, I end up using node to run a main.js like
node app/browser-app-template/src-gen/backend/main.js --hostname= --port=3000.
How do I add the cpp syntax highlight plugin to it?