Credits and deductions

What year are you preparing your return for? The option is there in the 2023 version of TurboTax Download Standard. If you are using EasyStep Mode, then enter your donation receipts, then go forward past the carry forward page, and you should get the option to split the credit.

If you are using Forms Mode, then override the line "Less: Amount claimed by your spouse or common law partner (if applicable)" on the Charitable Donations worksheet (DON). This override will not affect your ability to NETFILE.