To prevent leaks, it’s important that the protective cover’s front opening is sealed tightly.
To do this, make sure both flaps are straightened, for the flattest possible sealing surface. Then, fold the upper flap over the lower flap, and press firmly to seal tightly.
Note, the turquoise part of the upper flap doesn’t have any glue applied to it, so it should overlap the lower flap by approximately 0.5 centimeters.