Two-dimensional regular string black hole via complete $\alpha^{\prime}$ corrections

In string theory, an important challenge is to show if the singularity of black holes can be smoothed out by the complete $\alpha^{\prime}$ corrections. The simplest case is to consider a 2D string black hole or 3D black string. This problem was discussed in a gauged Wess-Zumino-Witten (WZW) model and the results are supposed to be correct to all orders in $\alpha^{\prime}$ corrections. Based on the recent remarkable progress on classifying all the $\alpha^{\prime}$ corrections, in this work, we re-study this problem with the low energy effective spacetime action, and provide classes of exact non-perturbative and non-singular solutions of the 2D black hole via complete $\alpha^{\prime}$ corrections.