New smart meter, got the app but can not put credit on it

Hi all
Got a new smart meter, Man installing said it would take a couple of days before i would be notified by bulb.
Not sure what i was waiting for?
App opens with the please top up.
Tried topping up with it and my banking app but that did not work.
Nothing on the app tells me how much credit i have.
Can any one help?
Thanks again
Alan

Forgot to add i can not top up online even, so at a loss at the moment

Just letting anyone know,that I have managed to top up. Although it was unclear.