Hi Artur,
Thanks you for reaching out. The "502:Bad Gateway" error while querying for the API reports could be a transient issue and retrying the request usually works. Could you please give this a try? If you're consistently seeing this issue, please share the complete request and response logs for me to investigate this further on my end.
P.S. Please use Reply privately to author option while sharing the details.
Regards,
Nikisha Patel, Google Ads API Team