The customer's password cannot be viewed in your order management system, but it can be resent to the customer. Navigate to Customers / (Last Name) / Click on the envelope next to the password. This will send the customer their password via email.
For a walk-through of this process, we recommend the Guided Tutorial called "Send a Password Reminder to your Customer". (Guided Tutorials are accessed separately from the Support Center in Foundry, through the link to Guided Tutorials in the system navigation. In the legacy standalone version of Nexternal they can be accessed through the Guided Tutorials link in the left navigation.)
For next time, you can also tell the customer about the "forgot password" function on the login page. If they click forgot login, they will get a temporary password sent to them automatically via email, and they will be instructed to change it.