TurboTax Online doesn't provide a copy of schedule 3. However, the detailed tax summary shows the bottom line calculations (50% of the taxable gain) on line 12700. The loss will be reported to CRA which you can carry back 3 years or carry forward to use against other taxable capital gains.
If you are reporting capital gains from a T5008 slip, you either fill the T5008 slip or complete the capital gain profile (use the search engine on the top bar) but not both.
I hope this was helpful
Heba
