Theme error

Hi. I’ve recently installed a plugin called Etsy360 to integrate my etsy store into my site. However it seems it’s not working due to errors in the Highend theme. I’ve tested all plugins and they’re fine and the plugin works correctly when I change to another theme. I have a screenshot of the errors from the plugin support team and will attach that. Can you take a look and tell me if this is something that can be corrected?

URL to affected page is https://www.tearohamassage.co.nz/inspiritgems/

When you add a product to the cart and then go to cart you’ll see the issue.

Thanks.