The representation theory of quantum groups at roots of unity was developed by De Concini–Kac–Procesi, and this has applications and connections in modular representations, Poisson geometry, and geometric representation theory. In this talk, we generalize the approach of De Concini–Kac–Procesi to quantum symmetric pairs. We construct the Frobenius center for $\imath$quantum groups at odd roots of unity and show that the irreducible modules of $\imath$quantum groups are parametrized by twisted conjugacy classes of the underlying Lie group. We further study dimensions of these irreducible modules. This is based on a joint work with Jinfeng Song.