How to authorize father to administer mother's medicines in assisted living?

In my mothers AL the AL nurse is in charge of medication. No residents are allowed to have it in their rooms. The Medtechs administer it.

If the AL is administering Moms meds, why do you want Dad too?

Is your father also a resident of the AL where your mother is? Without knowing that and if the AL requires medication to be administered by them which many do it is hard to proceed with answering you. Try to imagine the chaos that could ensue if many residents no doubt with memory issues were in charge of their medication. I hope you can provide more information.