Yeah I was hoping for other replies because this question was confusing to me.
If it’s the paper BPS certificate, yeah they probably need permission before they physically take it from you to hang up (why would they hang it up, that’s weird).
If it’s the actual displaying of the credential against your name, no, because you don’t actually own the BPS designation and that’s like asking if they need my permission to post my degree when writing “Confettiflyer, Pharm.D.” on a newsletter or something.