You can just ask the customer to try again after 5 minutes. If the issue persists, they can send an email to contact@zegsu.com for further assistance.
If the customer has already tried multiple times, inform them that you will escalate this to the development team to check,
Send an email to contact@zegsu.com with the issue description and the chat transcript.
The subject line should be: AliReviews - Captcha Hit Error - <shop name>