Please note this is a public user to user forum, not Magix Support.
Do not post order numbers, email address or any other personal information in the forum.
Assuming you purchased from Magix, the serial number should be in the purchase confirmation email you received, scroll down the page if you have the email, if not then check your email spam folder to see if it is there.
If there is no email then contact Magix by email to firstname.lastname@example.org
Note it is now the weekend so do not expect a response before Monday at earliest.