Fixed bug in OpenLibraryAPI when no isbn was present

Author: ltctceplrm

src/api/apis/OpenLibraryAPI.ts

@@ -70,8 +70,8 @@ export class OpenLibraryAPI extends APIModel {
 			dataSource: this.apiName,
 			url: `https://openlibrary.org` + result.key,
 			id: result.key,
-			isbn: result.isbn.find((el: string | any[]) => el.length <= 10) ?? 'unknown',
-			isbn13: result.isbn.find((el: string | any[]) => el.length == 13) ?? 'unknown',
+			isbn: (result.isbn ?? []).find((el: string | any[]) => el.length <= 10) ?? 'unknown',
+			isbn13: (result.isbn ?? []).find((el: string | any[]) => el.length == 13) ?? 'unknown',
 			englishTitle: result.title_english ?? result.title,
 
 			author: result.author_name ?? 'unknown',