Web (http) Commands for Power

[Wazambe]

I've used Tasmota 8.4 I think, and trying to access the Sonoff basic using web commands, referencing it's IP address.

For most commands like State, Status, TimeZone I can get feedback, and even make minor changes.
But there seems no way that I can trigger the relay.

Don't know what I'm doin wrong at all