Hi,

If the phone number is not appearing in your database, check the following:

    Ensure the phone number is populated on the delivery contact/customer record.

    Verify that you are using the standard delivery slip report and not a customized version.

    Check whether any custom modules or report modifications have overridden the default delivery report template.

So, under standard Odoo 19, the contact phone number on the delivery note is a built-in feature and should be displayed automatically when the relevant contact record contains a phone number.