I ran Auto-fill my return previously, however some of my tax slips were not yet available. I would like to run it again, but I don't see it in the menu or search. How?

If you are using TurboTax CD/Download in EasyStep mode, then you can find Auto-Fill by selecting Income & Expenses > Import Tax Data from CRA from the left side menu. If you are in Forms mode, select File > Import Tax Data from CRA from the left side of the top menu.