Using OP Miles to Upgrade on KLM
Tried the search, but couldn't find anything relevant so would appreciate the help:
Can a person use OP miles to upgrade a coach ticket to WBC on KLM?
If so, does a person have to purchase specific fare classes on KLM?
If an upgrade cannot be confirmed, is there a waitlist or does one have to call all the time to check availaibility?
Thanks!