Getting Solar Assistant to work

I am trying to get Solar Assistant set up to monitor and control my Growatt inverter from HA. I have downloaded and written to an 8GB micro-SD card the 64-bit version of Solar-Assistant, and plugged it into a Raspberry Pi Zero 2W. I have acquired the necessary USB/RS485 adapters and plugged them into the Pi, and the other end into the RS485 socket of the growatt. I have powered up the Pi (with a 0.75amp PSU - is this enough?). It does not create a SolarAssistant access point like it’s supposed to. How do I find out what is going wrong? Of course any of the above steps may not have been carried out correctly. The SD card may not have been properly written. The RS485 patch lead my have been incorrectly wired (I don’t think it was, but I could be mistaken), There are two possible wirings for this cable, as I understand it - I may have used the wrong one (but I would suppose that this would not stop it creating the access point, which presumably does not require access to the growatt). Any of the bits of hardware that I am using may be faulty. How do I debug this?

Thank you - Rowan