What is the password to login to this laptop ? the user is : user
This laptop has been fixed by Apple, the repair id is : R604618367
Question marked as
You really ought to ask the Apple Store that performed the repair, but if you are able to log into that Mac using your usual login credentials I would simply delete that User Account. I surmise it was created for testing purposes, contains nothing of value, and is no longer needed.
Delete a user or group on Mac - Apple Support
We have no way of knowing that password or can provide any insight regarding the creation of that User Account.