This application is useless. I have 2022 leaf sv and the last time it was working was on DEC 1. Keep trying the refresh button but it's stuck showing the DEC1 status.
I have 2022 SV and Leafspy can not disable the reverse sounds however for leaf models before 2020 leafspy can disable the reverse sounds. You will need OBDII device. It's a one time setting that does not require constant connection.
Don't use a charger that is not compatible. For 220V the original Nissan charger will output 6.6kW that is about 28A so I assume the "IONIQ" charger has an internal protection that will kick in if more than 20A is being drawn.