Form submission error to google sheet

I am submitting my contact form data to both Contact Form 7 and Google Sheets. While the data is successfully submitted to Contact Form 7, it is not being saved to Google Sheets. Upon inspecting the browser's network logs, I found the following error:

{
"success": false,
"errorId": 515,
"error": "",
"email": ""
}

I kindly request your assistance in investigating and resolving this issue.

Website URL: https://mytoxin.org/