I found that you identify humans with Google reCAPTCHA.
This is a problem for users in Mainland China: We cannot access
So we can't pass the test.
But Google also deployed reCAPTCHA on another domain, and we can access it.
So can you change the domain for reCAPTCHA to https://www.recaptcha.net/recaptcha/api.js
In this way, users in Mainland China can also pass the test.