Hello Zvonimir,
If you are looking for reach metrics, currently they are not supported in the AdWords API. You may check
this guide if a report attribute, segment or metric is available in the AdWords API or not. Also, you may follow our
blog for any upcoming features and updates. If your concern is different please elaborate.
Regards,
Sai Teja, Google Ads API Team.

ref:_00D1U1174p._5001UOCmv2:ref