This is either a Register Office or a Chapel marriage, so unless you know exactly which chapel, and you're lucky enough to find the register at the Flintshire Archives, I fear that the only way forward is to buy a copy of the certificate.
If you found the reference number on NorthWalesBMD, by clicking the link on the number, then again on the next page, you arrive at an application form to send to the Register Office at Mold.
Tecwyn
