I found that you identify humans with Google reCAPTCHA.
This is a problem for users in Mainland China: We cannot access https://www.google.com/recaptcha/api.js .
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.