If you forgot the password you set for your Keezel WiFi, you can easily change it. Please note that you will only be able to change it when connected to the Keezel WiFi, so you need to use a device that has connected to the Keezel before and therefore remembers its WiFi password.
If you don't have a device at hand that has previously connected to the Keezel and remembers the password, the only way to change the password is by resetting the Keezel:
In order to change the password via the Keezel's web-app, here's what you need to do:
While connected to your Keezel WiFi, go to keezel/ (or 192.168.11.1) in your browser.
Click on the hamburger menu (the 3 horizontal lines next to the battery indicator in the top-right corner of the page) and from the menu, click on Manage My Keezel Network.
There, you will have the option to change the Keezel WiFi's name and/or password.