In my experience, all you need is an RFID card of any sort to charge at a Chargepoint charger. As far as I can tell, the software on the charger reads the RFID and then tries to reach a backend that no longer exists. After a few seconds the API call fails, and the charger defaults to allow the charging session, possibly recording it in a buffer to bill you later, but that will never happen.
I have personally used a Chargefox card, but I am sure that an Evie or other might work as well. You might even be able to use an office key card and someone said a normal credit card might work as well, but this was not the case when I played around with it.
So, don't worry about any tricks, just enjoy.
By the way, the units on Kangaroo Island were something like 40A single phase, which gave me a much faster than expected charge rate.