You can add a 4.5” double hinged zinc plated safety hasp to secure the door on the Tycon ENC-ST-23x14x12 enclosure with a padlock.
An example of a suitable double hinged safety hasp can be found on Amazon or your local hardware store:
“https://www.amazon.com/dp/B0000CBIEL“
The safety hasp can be mounted to the enclosure using screws or rivets.
Be sure to waterproof the screws or rivets with silicon to prevent water leaks into the enclosure.