You can find it by clicking the Start button and looking in the pinned apps section. If it's not there, click on All Apps and scroll down until you find it.
Alternatively, you can press the Windows button on your keyboard and type Settings to quickly launch it.
You'll see this in the list of options on the left side of the screen.
Then scroll to the bottom of the list.
Locate the drop-down menu for Taskbar Alignment.