No connection with phone

I have a subscription to AVGtune up and the Antitheft function, but I am unable to use the latter.
There is no connection possible between my android device and the home computer. How do I do this? I have gone several times through all the prescribed steps but I cannot activate the antitheft functions  "no connection to the device" 

Hi Jacques, 

I request you to click on the link below and submit the request to our AVG mobile team.
Contact AVG Support - AVG Phone Number, and Chat Support (https://support.avg.com/support_contact_form?l=en&retUrl=support_Android_AVG_Antivirus)
Our team will contact you via email.