Thanks for the reply. So I guess this is why we are having a problem, I am using the latest version of Hass.IO, version 3.8, and it does not have a “hassos-boot” partition on the SD card. The only partitions are: hassos-overlay, hassos-data, 268MB Volume, and hassos-kernel. None of which contain a “config.txt” file. Which version of HA are you using when you got this to work?
OK! from your clues, I got it working! I wrote up the procedure: