From the regulation:
(ii) For an individual who does not have a residential or business street address, an Army Post Office (APO) or Fleet Post Office (FPO) box number, or the residential or business street address of next of kin or of another contact individual;
Assuming the center's manager is an individual; i.e. a contact person, you might reasonably use its physcial address or that of a relative. Whether their mail is delivered to either is not a factor.
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.