You must have Recorded Phone Calling enabled from the Account Settings section of your account in order to receive calls from your co-parent using TalkingParents.
You will receive an SMS text message from TalkingParents notifying you to expect a call. When you answer the call, a message plays stating that the call is coming from TalkingParents and will be recorded. You must consent in order for the call to be connected with your co-parent.