I am not sure about the latest Stern games but the Display normally states: " Insert Coins ". So it does not reference bills (the term we use for Note) or Tokens. I am not sure what the text would be if you change the games language away from English (like French or German).
One difference to keep in mind. The US "Domestic" games are designed to use a coin mechanism which measures approximately 3 inches by 5 inches and is designed to only accept one type and size of coin. There are usually 2 slots on these types of coin doors to hold two coin mechanisms. The export games usually are designed to use a single, much larger coin mech that is designed to accept multiple coins and usually requires special programming tools to accept the local type of coins. Some of these multi-coin mechs are intelligent and can "learn" which coins you want to use.
So, it may be difficult to buy a 3 inch X 5 inch coin mechanism that is designed to accept your coin. However, 0.900 inch and 0.984 inch tokens are very common in America. In Japan, the Pachislo or similar gaming devices typically use a token that is almost the exact same size as a US Quarter ($0.25). So if you get a batch of those tokens, you may find they work fine with the standard US Quarter coin mechanism. There is also a Canadian Quarter which is the same size as the US quarter. The only difference is that the Canadian Quarter is magnetic. Therefore, the coin mech cannot have a magnet as part of its slug rejection system.