Volume renormalization for complete Einstein--K\"ahler metrics

For a strictly pseudoconvex domain in a complex manifold we define a renormalized volume with respect to the approximately Einstein complete K"ahler metric of Fefferman. We compute the conformal anomaly in complex dimension two and apply the result to derive a renormalized Chern–Gauss–Bonnet formula. Relations between renormalized volume and the CR $Q$-curvature are also investigated.