The moment you received your parcel from DHL, you will be giving a DO - Delivery Order on that information it will stated your DMP Order No (Contain only 7 Numbers) ******
Note: SEND SMS to 63001 (unifi<space>ON<space>DMP No)
I HOPE THIS HELP, Thank you
I had the same problem. It is actually the digits in DHL tracking number. Duh. I tried and it worked. It is not the order number in email and SMS.