This is what we are going to try to find out. But no one can logically prove that a model is absolutely true. On the other hand, we can prove that a simulation model is consistent, but this seems too week a condition to rely on the simulation model. This is why we want to prove something more than mere consistency but less than an absolute truth. Actually, basically the same problem arises with scientific theory in general, and philosophers of science have tackled the problem in various ways.
All electrons have a negative charge.
According to the H-D method, we first create a hypothesis freely, and then test the hypothesis by checking a prediction from the hypothesis. A is observed. Therefore probably H is true. Therefore probably Newton's law of gravitation is true. The above scheme is a confirmation of Newton's law of gravitation by the observation of Mars.