Add check null value on keep log when submit

app/Http/Livewire/Pages/ManualResponse/ManualResponse.php

@@ -222,7 +222,7 @@ class ManualResponse extends Component
                 'detail' => "Username: " . $userConnect->username . "\nLink: " . $userConnect->link,
                 'xml_content' => base64_encode($this->xmlContent),
                 'reference_number' => $this->xmlData['ReferenceNumber'],
-                'declaration_number' => $this->xmlData['DeclarationNumber'],
+                'declaration_number' => $this->xmlData['DeclarationNumber'] ?? '',
                 'link' => $userConnect->link
             ]);