Probably not a HA thing but can I set my NUC to host all web traffic from internet connection and measure use?

I’m having issues finding out where gigs of data are being consumed on my network.
4G mobile broadband connection on TP-Link router. 40GB a month allowance.

The nuc hosting HA in docker is connected via copper cat5e link.
Is there a way of making all connected device (via WiFi traffic to the TP-Link router) route their traffic through a meter on the NUC?

I know i lost 6 gig last month on a laptop (on standby for days in a bag) getting windows updates!

Hmm. Not sure I want to go off topic.
Ask in discord #lounge or