fix generation

lib/submissions/generate_result_attachments.rb

@@ -36,6 +36,8 @@ module Submissions
 
     SIGN_REASON = 'Signed with DocuSeal.com'
 
+    UNSUPPORTED_IMAGE_TYPES = ['image/heic', 'image/avif'].freeze
+
     RTL_REGEXP = TextUtils::RTL_REGEXP
 
     TEXT_LEFT_MARGIN = 1
@@ -300,8 +302,9 @@ module Submissions
 
           field_type = field['type']
 
-          if field_type == 'image' &&
-             submitter.attachments.find { |a| a.uuid == value }.then { |a| !a.image? || a.content_type == 'image/heic' }
+          if (field_type == 'image' || field_type == 'stamp') &&
+             submitter.attachments.find { |a| a.uuid == value }
+                      .then { |a| !a.image? || a.content_type.in?(UNSUPPORTED_IMAGE_TYPES) }
             field_type = 'file'
           end