Payment Plan

I filed my federal taxes with the IRS electronically using Turbo Tax.  I owe just over $2,000.  When I filed I indicated I would pay lump sum by 07/15/20.  However, I letter went into the IRS website and applied for a payment plan, which was accepted.  My question is, do is just mail in checks to the IRS with my social security number on the check, or should I expect to receive vouchers from the IRS to include with my payment.  I'm thinking I should send my first payment this month of April.