  We provide a concise review on recent theory advancements towards
full-fledged (3+1)D dynamical descriptions of relativistic nuclear collisions
at finite baryon density. Heavy-ion collisions at different collision energies
produce strongly-coupled matter and probe the QCD phase transition at the
crossover, critical point, and first-order phase transition regions. Dynamical
frameworks provide a quantitative tool to extract properties of hot QCD matter
and map fireballs to the QCD phase diagram. Outstanding challenges are
highlighted when confronting current theoretical frameworks with current and
forthcoming experimental measurements from the RHIC beam energy scan programs.
