Hi Ankit,
Thanks for posting your concern.
My apologies as it is currently not possible to get the ad insights and purchases made by users using the AdWords API.
However, if you want to get audience metrics, you may try to use the Audience Performance Report and you can include the Ctr, (spent) Cost, Impressions, CpmBid and etc. Please note, however, that this is only aggregated at the userlist level and member/specific user level is currently not supported in the AdWords API.
Let me know if you have further questions.
Regards,
Ejay
Google Ads API Team