The shift tasks feature needs to be enabled by your administrator. It is a feature that you can use, or may be required to use, to track your tasks while you are on shift.
You may notice the following tab on your shift, called Activities:
Add Sign
You can also get a signature from someone to certify that you have in fact completed your duties correctly. Talk to your supervisor, as they may/may not require you to do this. For example, you may be asked to have someone at your work site "sign" that you have completed your tasks. Simply click the Add Sign button and ask the person to sign on your phone(if using the app) or let them sign on a computer. Again, this can be reviewed later by your supervisor as further validation that all duties that needed to be performed have been completed.
Log
The log is the next tab to the right of activities. This will show you all items related to your shift, including the items you added under activiites. For example, this will show you when you checked in, if you obtained a signature, attached a file etc. This allows you to confirm that the items you were supposed to complete or add to the shift are in fact there.