I’m unsure whether I’m pay monthly or prepayment

Hi, I used to be prepayment and used my app to top up every week.
My credit was running low so went onto app to top up and it’s now showing as pay monthly.
My smart meter at home is still showing as prepayment. I’m confused as to which I am.
I can’t use app to top up as it’s not giving me option only to set up monthly payments.
Will this automatically change on my unit at home? I don’t have a payment card to top up at shop!