X${}_1$(2900) as a ${\overline{D}}_1$K molecule

The analyses of the LHCb data on X(2900) in the D${}^{-}$K${}^{+}$ spectrum are performed. Both dynamically generated and explicitly introduced X${}_1$(2900) are considered. The results show that both these two approaches support the interpretation of X${}_1$(2900) as a ${\overline{D}}_1$K molecular state, with J${}^P$ = 1${}^{-}$ and an iso-singlet interpretation is much more favorable. The effect of triangle singularity on the production of X${}_1$(2900) is also discussed, and it is found that it cannot be interpreted as a pure triangle cusp.