Hi Viettel,
Thank you for reaching out. Can you confirm that you have followed the guidelines mentioned in
this forum post? If so, can you please provide your customer client ID as well as the complete detailed logs of the request and response so that I can take a closer look? Since we are currently experiencing issues with the "Reply privately to author" option, kindly provide these details in an email to
googleadsa...@google.com.
Regards,
Danica, Google Ads API Team

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