allow to draw signature on mobile

app/controllers/submit_form_values_controller.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class SubmitFormValuesController < ApplicationController
+  skip_before_action :authenticate_user!
+  skip_authorization_check
+
+  def index
+    submitter = Submitter.find_by!(slug: params[:submit_form_slug])
+
+    return render json: {} if submitter.completed_at?
+    return render json: {} if submitter.submission.template.archived_at? || submitter.submission.archived_at?
+
+    value = submitter.values[params['field_uuid']]
+    attachment = submitter.attachments.where(created_at: params[:after]..).find_by(uuid: value) if value.present?
+
+    render json: {
+      value:,
+      attachment: attachment&.as_json(only: %i[uuid], methods: %i[url filename content_type])
+    }, head: :ok
+  end
+end