Hi @KJoy3,
Deal tokens only work in automated emails sent from deal based workflows. In other words, a Sales Hub Professional subscription is required.
If you have one, you should be able to specify the association label of the contact you want to send the email to. When adding the automated email workflow action you should see a corresponding drop-down in the left sidebar.
Without association labels, this is currently not possible.
Let me know if I should elaborate any point in more detail!