Hi Shalu Khinchi ，
Thanks for the post.
The goal of the identity migration is to synchronize all possible users and to disposition any remaining unmapped records with justification as to why they are not synchronized. This synchronization and disposition process must be complete prior to preparation of user acceptance testing.
You could refer to the official documentation to overview the process of Identity Migration:
I hope I can offer you a better experience next time if I have a chance to work with you again.
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