I am a newbie... but what is the "rated/ideal range"?
There are industry standard test cycles. USA uses one called EPA, and Europe used NDEC (recently replaced by the WLTP standard). These test cycles are supposed to represent standard driving conditions - go X miles at speed A, then Y miles at speed B, then Z miles at speed C, etc. Often they try to represent combinations of city and highway driving. The car manufacturers fill up the 'tank' of the car, drive the test cycles, and see how much fuel is used. In the case of EVs, they charge to full, drive the cycles, then charge to full again (measuring the amount of electricity that goes in). That gives the published fuel economy figure for the car. When advertising a vehicle's range (or fuel economy figure), the manufacturers must legally use these figures. The manufacturer is allowed to declare/advertise the range as less than the tested range, but never more. It is important to note here that nobody is lying or falsely advertising ranges. The purpose of the system is to make sure that different cars can be fairly compared, not necessarily that the range you will achieve in the real world will match that advertised.
Tesla HK currently advertises Model 3 Standard Range Plus as 409km, Long Range as 560km, and Performance as 530km, using the WLTP test cycle. Those are the ideal/rated ranges that the car will show you.
The other range you can see is the estimated range based on your driving patterns. To show you that, the car looks at the actual energy used by your recent driving (for example, the last 40km), and uses that to estimate how far you can go. However, unless you are driving the same way on the same roads, in the same conditions, this can be inaccurate. Imagine driving back from the airport at a moderate speed (highway, so very efficient), your estimated range would be very far. But then you get into central traffic jams and try to head up to the peak - your actual achievable range in that example would be nowhere near estimated (perhaps less than half).
It is likely that neither will match what you actually get. I am an unusual case in that my commute to work is a mix of city and highway driving that almost exactly matches the NEDC cycle, so I get almost exactly the ideal/rated range of my car.