use sidekiq

app/controllers/api/submitters_controller.rb

@@ -66,7 +66,7 @@ module Api
       end
 
       if @submitter.completed_at?
-        ProcessSubmitterCompletionJob.perform_later({ 'submitter_id' => @submitter.id })
+        ProcessSubmitterCompletionJob.perform_async({ 'submitter_id' => @submitter.id })
       elsif normalized_params[:send_email] || normalized_params[:send_sms]
         Submitters.send_signature_requests([@submitter])
       end