Off-mode means that Mysa thermostat won't be sending power to the floor heaters. The Mysa thermostat will still be on but won't be turning the heaters on. This setting can be enabled on the Mysa thermostat itself or in the Mysa app.
On the Mysa thermostat: Hold down the down arrow until you see three dots on the display. Let go of the down arrow. The thermostat is now in off mode.
In the Mysa app: Tap the tile of the Mysa thermostat you'd like to turn off. Press the icon in the bottom left corner and a pop-up menu should appear. Tap off-mode, which is visually represented by a plug.