Regularity for almost minimizers of a one-phase Bernoulli-type functional in Carnot Groups of step two

We prove that nonnegative almost minimizers of the horizontal Bernoulli-type functional $$J(u,\Omega):=\int_{\Omega}\Big(|\nabla_{\mathbb{G}} u(x)|^2+\chi_{\{u>0\}}(x)\Big)\,dx$$ are Lipschitz continuous in the intrinsic sense.