If you want to update your age in your Wizz account, you have to:
👉 Go to your Profile (tap your picture on the top-left corner)
👉 Go to your Settings (tap the wheel on the top-right corner)
👉 Tap on the wrong birth date, then tap "Update My Age" and enter your birth date (only within the limit of +11 months or -11 months)
👉 Tap "Save" once you're done 😄