The ALL3073v2WLAN provides a JSON API to switch on or off the power for the attached device.
In order to enable 230V power for the attached device, use this URL (HTTP GET request):
http://IP-Address-of-ALL3073/xml/jsonswitch.php?id=1&set=1
In order to disable 230V power for the attached device, use this URL (HTTP GET request):
http://IP-Address-of-ALL3073/xml/jsonswitch.php?id=1&set=0
Note that id=1 will always stay the same since 1 is the ID of the actor controlling the power, just set=0 or set=1 are different,