Configuration of GET RECORD

Hi there!
I was following the video instructions where AppGyver was connected with API from Xano, and trying to configure GET RECORD in DATA , and after TEST run, I get the exactly the same JSON as I get running TEST in GET COLLECTION, and it supposed to contain the second part as following:
“_reviews_of_books”: [
“created_at”: …
“books_id”: …
“comments”: …
as a result my books app open the books_details page, but it’s empty. Can you help, please?