Courier API error: Missing mandatory data in 'Service' 'PSD'

Cause
This error occurs when no email address is present on the order, and MyGLS requires an email address for PSD service (locker delivery). 

If email addresses are not collected at checkout, MyGLS validation fails during label creation or shipment submission.

Solutions

1. Add the email manually on the specific order.
2. Enable auto-fill to insert a placeholder (dummy) email when missing.

Check here the settings to add automatically a fictive email address

https://xconnector.freshdesk.com/support/solutions/articles/103000320734-automatically-add-an-email-address-to-the-order-when-the-email-field-is-empty