Shortly after the formulation of special relativity, Einstein's former math professor Minkowski found an elegant reformulation of special relativity in terms of the four dimensional geometry that we call today Minkowski space. Einstein at first rejected the idea. (`A pointless mathematical complication'.) But he soon changed his mind and embraced it full heart, making it the starting point of general relativity, where Minkowski space is understood as the local approximation to a four-dimensional, pseudo-Riemannian manifold, representing physical spacetime.This is cleverly written to convince you that Minkowski derived a 4D geometry version of relativity from Einstein's work. This is not true.
The mathematics of Minkowski and general relativity suggested an alternative to Presentism: the entire four-dimensional spacetime is `equally real now', and becoming is illusory. This I call here Eternalism.
Poincare was the first to formulate a 4D geometry version of relativity, and that paper was written before Einstein published anything on the subject. Minkowski's 4D space was developed directly from Poincare's work, not Einstein. Minkowski does cite Einstein's paper, but does not use anything from it, and it is not clear that Einstein had any influence on Minkowski at all. From Poincare's paper, Minkowski gets the 4D formalism, the pseudo-Riemannian metric, the 4D Lorentz transformations, and the 4D covariance of Maxwell's equations.
This subtle mistake of McTaggart is the same mistake as that which lies at the root of Eternalism. The ensemble of the events of the world is four-dimensional, and we can embrace it within a single image. But this is not a denial of becoming, no more than a single chart of the British royal dynasties is a denial of the fact that events happened in England along the centuries.Rovelli is right that believing in relativity and using Minkowski does not a belief that all times exist at once. Some people seem to believe that relativity requires determination and a denial of the present. One can still have different philosophical views of time.