How to pass arguments into module

I want to access the modeler in my custom module which is a class

Is it possible to do?

Obviously the modeler doesn’t exist yet at this stage.

      additionalModules: [
        {
          customFunctions: ['type', CustomFunctions(this.modeler)],
        },
      ],

You can access the bpmn-js modeler (or viewer) instance using the bpmnjs name.

So something like:

export default function MyCustomModule(bpmnjs) {
   ...
}

MyCustomModule.$inject = [
  'bpmnjs'
];