Postman is a great tool to use for merging duplicate profiles in Mixpanel
Sometimes when working with Mixpanel you run into an issue where you have duplicate profiles. Luckily Mixpanel has an API endpoint for this. One of the easiest solutions is to connect your postman account with their API. Here is the code that we use to do this.
All you need to do is replace the project ID, and the two id’s that want to merge and send a post call.

The Post Call: https://api.mixpanel.com/import?project_id=project_id&strict=1
You can find more information here in Mixpanel developer documentation