The reason you cannot see the complete gift card number is because your organization has enabled the setting to “Mask the gift card numbers to all users”.
This means, wherever displayed, you can view only the last 4 digits of the gift card number and the remaining digits are masked with an asterisk (*).
Only employees with the required permission can view the complete gift card number and this permission is enabled for the owner role by default. Read: Masking Gift Card Numbers.
How do I view the complete gift card number?
If you need the complete the gift card number, you must ask any employee who has the permission to view the complete number or simply ask the guest for it.