fix: config not exists (#2513)

web/app/components/base/chat/chat/answer/operation.tsx

@@ -74,7 +74,7 @@ const Operation: FC<OperationProps> = ({
         )
       }
 
-      {(!isOpeningStatement && config?.text_to_speech.enabled) && (
+      {(!isOpeningStatement && config?.text_to_speech?.enabled) && (
         <AudioBtn
           value={content}
           className='hidden group-hover:block'