Does the first payment have to be by mail for a payment plan?

I picked out a payment plan but now im not so sure.  I don't like mail and would rather have all payments go straight out of my account. But I think the first payment has to be by mail and its honestly freaking me out since I plan on moving within a couple of weeks. I'm really stressed out about this I just don't want to have to worry about mailing when it can just easily be taken out of my account.