Data usage for the Nuki Bridge

Does someone know how many data (internet) the nuki bridge needs when a Nuki Lock and the Nuki Opener is installed?
Does it depent on how often it will be opened? Are there repetitive calls to the nuki servers to check for new opening requests or how does it work?
I tried to use Wireshark to capture the traffic but it does not capture it on my mac : /

I want to use the Nuki Bridge with a mobile plan where every MB costs.

Greetings

The actual data transfer depends on how much you use it, but it is generally speaking quite low as the bridge only transfers data that would normally be transferred directly via BLE (which is a low bandwith protocol). Most of the data is actually used to keep the connection to the server alive (~30MB/month). With normal home use you should end up with <50MB/month in any case.