You can activate DNA Connect from the very moment you create your tellmeGen account. If you haven't done so yet, simply log in to your account, go to "Settings" → "Kits" → "Privacy" and select "I want to participate in DNA Connect and discover genetic relatives".
If you wish to deactivate the service at any time, you can also do so from the same place in your account. Go to "Settings" → "Kits" → "Privacy" and uncheck "I want to participate in DNA Connect and discover genetic relatives".
If at any point you chose "Do not show again" in DNA Connect and want to access the service again, simply log in to your account, click on your initials in the upper right corner, go to "Settings" → "Kits" → "Privacy", and select "I wish to participate in DNA Connect and discover genetic relatives" again.