Can I add more lines to T1135 Part B7 in online version?

If you have more entries you will have to print the form and add the extra lines and mail it to CRA:

https://www.canada.ca/en/revenue-agency/corporate/contact-information/where-mail-your-paper-t1-return.html

If you want to efile it > you can combine entries in one line to be able to efile the T1153 > this will not drop the requirement of mailing the form after with a letter of explanation.

I hope this was helpful 

Why have you not fixed this. People have been asking for this for years!!

When is TurboTax going to fix this? It is now 2023.