Do I have to wait for short term payment plan to be approved (send voucher with check) before changing to a long term plan?" Return was accepted w/ Short term vouchers

I did not know I was entered into a short term plan till return was accepted and printed it out. It now contains a voucher for initial payment and yearly quarterly payments, Is the IRS expecting an initial payment because of voucher in print out with return? I want to change to a long term payment plan.