You can turn on AirTriggers from [Settings] > [Advanced] > [AirTriggers]. You can also turn on AirTriggers in [Game Centre] > [More options] at the top right corner > [AirTriggers].
From this setting path: [Settings] > [Advanced] > [AirTriggers], you can also set up [Squeeze force level] and [Button tap force level].
In addition, you can set up to use [Short squeeze] and [Long squeeze] to trigger certain features or launch specific apps when the screen is locked or after it has been unlocked.
Moreover, you can also quickly turn on AirTriggers and enter its settings via [Quick Settings]. Tap [AirTriggers] in [Quick Settings] to turn it on or off.Long press [AirTriggers] to go into its advnaced settings.