If you need a customer to print the 3-part special delivery ticket format, follow the instructions below.
Open D365 and navigate to
Accounts receivable >> Customers >> All customers
Find and open the customer account you want to change.
Change into Edit mode.
On the Invoice and delivery fasttab, turn the Special delivery ticket option to "Yes".
Save the customer record.
Now, when printing the Packing slip, it will use the Special delivery ticket format.