You can go back and delete the duplicate T4A.
How to Delete T4A Slips in TurboTax Online:
1. In the upper-right corner of your screen, select Find (magnifying glass)*.
2. In the Find window, type in “T4A” and select “T4A Pension, Retirement, Annuity”. Click the “Go” button.
3. Click the “Delete” link next to T4A that you want to change.
If you have TurboTax Live Assist & Review, see this TurboTax FAQ to learn how to talk to a Tax Expert or book a review: In TurboTax Live Assist & Review, how do I talk to a tax expert?