The (elliptic) stochastic quantization equation for the (massive) \(\cosh (\beta \varphi )_2\) model, for the charged parameter in the \(L^2\) regime (i.e. \(\beta ^2 < 4 \pi \) ), is studied. We prove the existence, uniqueness and the properties of the invariant measure of the solution to this equation. The proof is obtained through a priori estimates and a lattice approximation of the equation. For implementing this strategy we generalize some properties of Besov spaces in the continuum to analogous results for Besov spaces on the lattice. As a final result we show how to use the stochastic quantization equation to verify the Osterwalder-Schrader axioms for the \(\cosh (\beta \varphi )_2\) quantum field theory, including the exponential decay of correlation functions.