Alert notifications using employee's first name

Summary:

We would like to send alerts to employee's using their first name, but this does not appear to be possible. The way our display name was configured on implementation was not ideal but there were business reasons for this hence why I am seeking a way to do this using their first name. I have tried to use {FirstName} in the composer but obviously that is not a value available as it comes through as "null". Is this possible and if so how?

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