The included lanyards are used to secure the Oculus Touch controllers to your wrists during use.
To connect the lanyards to your Oculus Touch controllers:
Pick up one of your controllers and remove the magnetic battery cover by lightly sliding your thumb down the battery door until it comes loose.
On the inside edge of your controller, below the open battery compartment, you'll see a circular cut-out. Slide the plastic end of your lanyard into the small hole in the centre of the circular cut-out. When the lanyard is seated correctly, the plastic piece sits entirely inside the hole.
Slide the string of your lanyard downwards so that it's sitting in the lanyard cut-out at the bottom of the controller. If it's seated correctly, it won't obstruct the battery door cover you removed in step one.
Slide the magnetic battery door cover back into place until it clicks and sits flush against the controller.
Before using, pull down on your lanyard to ensure that it's securely connected to the controller and doesn't unseat the battery cover.