If you are unsure about where in Smartplan you can start synchronising your shifts, yo might benefit from our two guides:
At this point, you should see this page, in which you can click on "Add to iPhone/Mac" in order you synchronise to your iPhone:
Then you can click on "Subscribe":
The Smartplan calendar has then been added to your phone:
When you take a look in you calendar you will now be able to see when you have to work: