Structured data report Google Error

Hi!
First of all I would like to thank the developers for the work they have done. I like this plugin.
But after reviewing Google’s structured data tool, I found 2 errors.
1. asin – Google does not recognize the ASIN property as a Book type object.
2. tag – Google does not recognize the tag property as a Book type object.

The first error I could solve by deleting item itemprop = “ASIN” in file templates.php

$ output. = empty ($ unique_id)? ”: ‘<span class = “mbt-meta-item mbt-meta-asin”> <span class = “mbt-meta-title”> ASIN: </ span> <span>’. $ unique_id. ‘</ span> </ span> <br> ‘;

The second error with “tag” I can not solve.
Please, if possible, indicate the steps to solve the problem.
Thank you!

The page I need help with: [log in to see the link]