Unique id to identify each user unique purchase

[shankarbhattarai123]

I got a issue that when in my device i am logged in from one Gmail account called "abc@gmail.com" and in my app i am logged in from user 1. I purchased from user 1 and logged out from user 1. I signed in with different user in my app called user. Now when i try to restore purchase history i got user 1 purchase history. Now how can i track purchase history of each individual user although Gmail/playstore login is same for all user. Is there any way. Please give me some solution.