delayed_paperclip with sidekiq returning NoMethodError: undefined method `fetch' for nil:NilClass

Question

I am using delayed_paperclip and I have tried it with the default ActiveJob and it works well. However, it runs synchronously so it will wait for the job to finish before response so I wanted to move the queue to sidekiq.

But now that I have moved the queue to sidekiq, it gives me an error:

NoMethodError: undefined method `fetch' for nil:NilClass

I have tried looking for answers but I found no luck.

I added this to my application.rb

config.active_job.queue_adapter = :sidekiq

my Image model

    has_attached_file :attachment,
                  styles: {
                      mini: '48x48#',
                      thumb: '75x95#',
                      tile: '212x212#',
                      tile_portrait: '230x327#',
                      large_tile: '300x300#',
                      small: '100x100#',
                      product: '240x240',
                      large: '360x460#',
                      large_portrait: '460x654#',
                      zoom_portrait: '690x981#'
                  },

    process_in_background :attachment, processing_image_url: :processing_image_fallback

    def processing_image_fallback
      options = attachment.options
      options[:interpolator].interpolate(options[:url], attachment, :original)
    end

Does anyone know what the problem is? or is there a way that I can just use ActiveJob but how can I make it process the paperclip in the background?

Here is my image upload code also

def create_images
  return if context.image == {}
  context.images.each do |key, image|
    new_image_record = Image.create(
    kind: context.type
  ) #what I want to achieve: move on to next after creation 
  new_image_record.attachment = image
  new_image_record.save #job runs here. hoping this will run in the background or be moved to sidekiq
end