jsonapi-resources custom action

Question

I need to add a custom action to my jsonapi-resources controller. This action just creates e new version of a preexistent CollectorContent model instance. My implementation (just copied from here):

routes.rb

jsonapi_resources :collector_contents do
  member do
    post :create_version
  end
end

collector_contents_controller.rb

class CollectorContentsController < ApplicationController
  def create_version
    cc = CollectorContent.find(params[:id])
    cc_new_version = cc.create_version!
    render json: resource_serializer.serialize_to_hash(CollectorContentResource.new(cc_new_version, nil))
  end
end

Even if it works it seems that adding a new action in the controller is not the recommended way but I don't understand how I can use a operation processor to implement my use case. Can you help please?