After upgrading to the October release there is a new Tuya integration (2021.10.0: Z-Wave S2 support, Tuya, secure ESPHome and 400 new icons - Home Assistant). I followed the instruction to set it up against the IoT API service (Tuya - Home Assistant).
The instructions worked until I the addition/configuration in home assistant. I would always get the error message 2406: skill id invalid… According to the page that mean that the cloud project should be created after May 25, 2021… It is October now, not May. After some trial and error I testet to change the country I give in the configuration… The country I used first and that I’ve used with Tuya app and IoT is Norway, but that always gave med the 2406 error… I changed the country in the home assistant configuration to Sweden and everything works fine now. So I believe there must be some error in the country code that home assistant config sends with my country (Norway)