The template contains premade BPs which contain a Trigger and a camera which defines a fixed camera. When the player enters the trigger, the camera will be activated.
At this point, there are two types of cameras: Regular fixed and Dolly cameras, which also contain a spline to follow the player’s movement.
Press the Fixed Camera button on the toolbox

This will instantiate a camera in the level

On the Details panel, select the BoxTrigger component and adjust it position and extents to cover the area in which this camera will be active

Finally, place the viewport window camera with the position and rotation you want your Fixed camera to have. Once you are happy with the POV, select the FixedCamera BP again and press “Match Viewport POV” to automatically move the camera component to the viewport POV.

If you created a Dolly Camera from the toolbox. Select the Spline component and modify its points to define the camera range of movement.