Here's the procedure for deleting the form in TurboTax Online:
Open TurboTax Online
Select Tax Home in the left pane
On the Hi, let's keep working on your taxes! screen, select the dropdown on the right side of any box in the middle of the screen, then select Start or Review/Edit
After more topics will generate in the left pane, select the Tax Tools dropdown
Select Tools
In the pop-up window Tool Center, select Delete a form
Select Delete next to Form M1PR and follow the onscreen instructions