So yours probably came with a grey Cat5 to Serial connection.
View attachment 186915
You would need a Serial to USB converter if it didn't come with the inverter. I know newer inverters came with an all black cat 5 to usb that was a solid piece, but I think yours is a little older.
This cable is the battery BMS cable. It doesn't work for inverter firmware.
View attachment 186918
Since your inverter has an AC IN connection, you would want to set option 42 to ENA. This disables the G/N relay inside the inverter and creates a common neutral, passing the bond from your main AC panel.