You would fill out each slip individually within the program, and then the program will do any calculations required.
You can use the Find tool in the top right to search for “T-slips”. Then select T-slips from the list and click the Go button. Check off all the different types of slips that you have. If you don’t live in Quebec, be sure to check off the “I worked in Quebec and received a Relevé 1 slip” after you check off “T4 - Employment Income”. Once you are done with that, click the “Continue” button to go through the different slips and enter your amounts just as they are shown on your paper slips.
If you have signed up for CRA My Account, you can also just use the Auto-Fill feature to import your slips instead of typing them in.
Here is how to use the Auto-fill My Return service in TurboTax Online: https://turbotax.community.intuit.ca/replies/2994684
Here is how to use the Auto-fill My Return service in TurboTax CD/Download: https://turbotax.community.intuit.ca/replies/3008672