My wife has the same machine (so I could look at the details). The power "brick" that goes between the cord that plugs into the wall and the cord that plugs into the CPAP has markings on one side that explains what it can utilize for input power. In this particular case it is marked something like: Input Voltage - 120-240 VAC, 50/60 Hz. The US uses 120V, 60 Hz power - the countries you'll be visiting in Europe use 240V, 50 Hz. This means that your power supply will work fine in any of them.
There is one issue - the wall plugs in different countries use different shapes - you can't simply plug in a power cord from the US into an outlet in England, Italy or the Netherlands. Look at:
https://www.worldstandards.eu/electrici ... d-sockets/ . For London, you'll need an adapter for Type G (US socket - British Plug). Italy and Amsterdam use the same shape plugs: Type C or F.
You can get adapters for these plugs on Amazon or other places (best to get them before traveling).
Most modern power supplies (phone chargers, PC power bricks & so on) will work in Europe as well as the US - but always look for the markings on the power brick that say what input can be used.