tasmota static ip

https://github.com/arendst/Tasmota/issues/2219

Use Web Console and enter
IPAddress1 192.168.1.2
will do that

or use the command on Web line, e.g.
http://sonoff/cm?cmnd=IPAddress1%20192.168.1.2

see Wiki Commands for WiFi

I think Console was designed for all what