If you have lost your confirmation of registration, you can apply for an extract by post by sending a letter with a copy of a valid ID to:
Attn. Afdeling CVE2
P.O. Box 70013
3000 KR Rotterdam
Or you can request one online using DigiD via this webpage.
You can also call 010-2671625 to make an appointment at Town Hall for ‘uittreksel BRP’ to apply for the extract in person.