No offense, but there’s your problem. The topics get pretty big, but best to scan, search, or at least skip to the bottom-ish part to see what’s current next time. Any Tuya type device (which a lot of ESP82XX devices are) manufactured after July-ish 2020, and virtually all made or bought after October 2020, will have new / patched TUYA firmware that prevents custom OTA flashing (e.g. tuya-convert). If you want to flash this, or any other new TUYA type product at this point in time, you’ll have to open them up and serially flash them (e.g. solder wires to a USB type device, etc.). No way around it until the very big IF day that someone finds another firmware vulnerability to exploit for OTA flashing again.
Edit: just wanted to add that there are other switches out there that are easier to open / flash than this one. The Feit dimmer’s biggest hurdle is the need to desolder the TYWE2S module (the part that contains the ESP chip) in order to get to the necessary pins. Some dimmers and what not have pin headers, or at the very least easy to get to pin points to solder your connector to. If that’s still too much or just beyond what you think you can do (it’s ok, not everyone is an electronic guru ), then your best bet is to either find maybe some used or old new stock on ebay, offerup, etc., or look for some of the few switches out there that actually come with Tasmota already on them (see here). Alternatively some devices (e.g. Shelly, etc.) have firmwares that allow local control with built-in MQTT and/or HTTP functions, which will let you do many of the same things you might do / want with a custom firmware flash. You’ll have to Google a bit for those, but that’s really the only way for now to avoid doing the dirty work yourself.