How to cancel/downgrade plan while on trial

Feeling a bit silly but the desktop of Ring's account management wasn't working so I added a new site on the phone app/browser and didn't realise it signed me up to the higher level plan (Plus?) instead of Basic.The FAQ instructions tell you to cancel then sign up again, but there's no option to cancel (I assume as it's a new device at a new site it's still in trial for a month).I'm not really keen on leaving it until billing starts - even if I cancel day one I assume I will be billed the first month or at least day at the higher plan rate, and that's if I even remember in a month to downgrade the plan.I'm in Australia and the COVID19 contact details page only lists options for US and UK in English, as well as regional European lines.Any ideas?