Toll roads in Belarus do not have gates or toll booths when entering or leaving road. There are only signs that Toll Road starts.
In order to use toll roads, you need to rent a Beltoll system device and install it in your car before entering a toll road.
You can rent a device and pay for your trip at selected gas stations near country border. details about Beltoll
... drive and not pay? It is not worth it, there are cameras on toll roads. Large mandate will be waiting for you on the border.
Maps.me - download application and Brest region map. Then you can use them without Internet.