Thank you very much for helping me with this one Nayeli! 
I already tried your code. The email, first and last name, are now inside my own database (MemberPage), but unfortunately, the _id in that database still didn’t match with the _owner which has the same value as the contactId in the PrivateMembersData. So in this case, I cannot open My Profile Page which has a link as shown in the right side of the picture.
So this is the reason why I wanted to make the _id have the same value as the _owner or contactId