Can't load mobile app from home after being in the branch and now it is closed with covoid and my mother is 84 years old????

Good day

I take my mother of 84 years Mrs Elaine Purves born 1936 to the Meyerton branch to have power of attorney on the account, which was successful after an hour or three due to who knows. The whole idea was to be able to manage my mother's account from my phone due to covoid. They told me after the almost 3 hour wait that I can add the banking app from home, which I so then did. Once I added the app head office calls and refuses me this opportunity I have to return to the branch with my mother in Meyerton which is now an epicenter of the covid virus and the branch is closed due to infection????

How can I be assisted? My mother is going to inherit from my fathers E/L and it is all just becoming very complicated when it is a simple procedure. Please assist.