The base station (receiver) is delivered without a power cable. This fact is not clearly stated. In the UK, where the importer is located, it may be customary to mount mains-powered devices (230VAC) directly to a 'dry lining box', whereas on the continent a cable with an EU 2-pin plug is the norm. Removing the transformer-end plug from unused laptop power cable is a solution.
Testing the radio link between the remote (thermostat) and the base station is not possible until the boiler is wired to the base station.
On the continent, wireless thermostats are generally purchased from the manufacturer of the boiler. The prices of 'branded' devices often are a multiple of what an 'independent' manufacturer asks (4X is not unusual) and boilers with support for the OpenTherm protocol are suitable for many of their current offerings. N.B. - 'OpenTherm' is compatibility between boiler and thermostat, including ones from independent manufacturers