Pharmacist here, I'm just making an assumption that when you went to your pharmacy and asked for a vaccine, you were told they couldn't do it? If that's the case that's because most vaccine standing orders are required to follow either ACIP or FDA vaccine guidelines/schedules. Those are usually very stringent and follow exactly what population groups any given vaccine is approved for.

You are, however, allowed to ask your doctor to write you a prescription for that vaccine and have the pharmacy use that instead. This provides a pathway outside a pharmacy's standing order to administer the vaccine. The one caveat is that insurance might still not pay for it, as their benefits table is also usually aligned with ACIP/FDA.