Is it possible to require a field in the Help Center but not for an Agent?

Is it possible to require a field in the Help Center but not for an Agent?

It's nice to have required fields in the Help Center, but if a client submits an email directly, I don't want those fields to be required because making any change means each required field needs to be filled in, and we won't necessarily have the info.

So my question: can a field be required in the Help Center, but *not* for the agent when updating the ticket?