Procedure to get a EU DUNS Number for Apple Business Manager 

If you own or run a business in the EU and want to apply for Apple Business Manager you need to request a Dun & Brandstreet DUNS number.

Currently you have to send a request to Dun & Bradstreet support: https://support.dnb.com/?cust=appleabm

You have to submit a case and send you company registration details.

Usually the procedure takes at least a few days, but sometimes as long as a few weeks.