It is a criminal offense and a human rights violation, to demand somebodys medical information against their will.
Therefore you do not have to tell anybody whether you took the jab or not.
They will also be breaking the law, if they fire you or deny you service over it.
So far nobody has tried it with me, but i do have experience with this regarding face masks.
Several grocery store owners and a bank tried to deny me service for not wearing a mask.
I did a silent prayer to Yehovah, then i stated i am medically exempt, that i wont show them proof because i dont want to, they cannot further demand to see it or deny me service, because i will file discrimination charges against them.
All of them backed off!