fix

app/Modules/Book/Services/BookConfigService.php

@@ -498,7 +498,7 @@ class BookConfigService
                 $book = $books->where('id', $item->bid)->first();
                 return [
                     'bid' => Hashids::encode($item->bid),
-                    'cover' => $item->cover,
+                    'cover_url' => $item->cover,
                     'book_name' => $item->book_name,
                     'intro' => $book->intro,
                 ];