Hard to say without measurement, but it does look like M30x1.5, in which case, you dont need any adapter at all, you can screw the TRV on directly.
If it doesnt fit, this should help:
Could it be 26mm? The PDF linked at the bottom of the article I linked shows a "Pintossi" 26mm which requires an adapter, its lists the adapter name and EAN code.
If its the 24mm Landis & Gyr, they you appear to be out of luck
If its neither of those, contact tado support directly.
To calibrate the TRV must feel resistance at the end as it pushes the pin in (close the valve), and little or no resistance as it opens the valve. Ive managed to fool one with my finger, just pushing hard when its almost fully extended.