If you want to see how your plan changes through paying off debt early, you can model making lump-sum payments through My Plan > Money Flows.
Go to My Plan > Money Flows
Create a Transfer by pressing "Add a Transfer +"
Select which account will fund the payment
Select the account or disbursement that will receive the payment (e.g., Primary Home Mortgage, Credit Card Account, Student Loan, Rental Mortgage, etc.)
Enter the amount for payment
Enter the year "You" will be when you make the payment (even if the payment is towards your spouse's account).
(Optional) Add a note to keep track what this transfer is for