Right after the check box for this, you can enter the date.
From the Lacerte help key I found what will also apply to PTO:
"The program uses a default electronic payment date of April 15, 2020 for returns filed before and on April 15, 2020. For returns file after April 15, 2020, the electronic payment date will be the transmission date. Enter the date, in mm/dd/yy format, you want the debit of the electronic payment to take place before April 15, 2020. The program will not allow you to enter a date later than April 15, 2020."
For this year, replace April 15 with July 15.