You can have a camera reset its Wi-Fi credentials in memory by holding the physical reset button at the back of the camera for 10 seconds, then releasing.
You will then see the camera reboot and you should hear the "ready to install" chime, as the camera is expecting to be installed.

 

Note that you can only re-install a WiZ camera in the same WiZ home using this technique. A anti-theft mechanism is in place and the installation will fail if you try to install the camera in a different WiZ home.
In this case, and if you are the rightful owner of the camera, please contact the WiZ in-app chat support and they will help you with deleting previous installation of the camera to make it available to be installed in a new home.

Note that if you select "Delete" for a camera from the WiZ app, it will be available to be installed in any WiZ home (not only its previous one).