The message "your connection is not free of charge" is not related to the camera but to your mobile subscription.
If you do not have a monthly phone plan or you use mobile internet data (4G / 3G) beyond the limits of your plan, the operator will warn you that you can be billed for this.

This depends on your subscription settings.

Example: if your subscription includes 1GB of monthly internet traffic, the connection should be free as long as you do not pass your plan's 1GB limit (this is the case for most subscriptions/plans).
If you are connected to a Wi-Fi network at some other place (friend's house, hotel, etc) this will also be free of charge, as your connection is going through the Wi-Fi network of the place at which you are located.

Do not hesitate to confirm this yourself by contacting your mobile supplier.