  Inspired by recent observations of $T_{c\bar{s}0}(2900)^0$ in the $D_s^+
\pi^-$ invariant mass distribution of $B^0 \to \bar{D}^0 D_s^+ \pi^-$ decay and
$T_{c\bar{s}0}(2900)^{++}$ in the $D_s^+ \pi^+$ invariant mass distribution of
$B^+ \to D^- D_s^+ \pi^+$ decay, we investigate the $T_{c\bar{s}0}(2900)^{++}$
contribution to the $B^+ \to K^+ D^+ D^-$ decay in a molecular scenario, where
we consider $T_{c\bar{s}0}(2900)r^{++}$ as a $D^{\ast +} K^{\ast+}$ molecular
state. Our estimations indicate that the fit fraction of
$T_{c\bar{s}0}(2900)^{++}$ in the $B^+ \to K^+ D^+ D^-$ is about $12.5\%$, and
its signal is visible in the $D^+ K^+$ invariant mass distribution. With the
involvement of $T_{c\bar{s}0}(2900)^{++}$, the fit fractions of
$\chi_{c0}(3915)$ and $\chi_{c2}(3930)$ may be much different with the ones
obtained by the present amplitude analysis [Phys. Rev. D \textbf{102}, 112003
(2020)], which may shed light on the long standing puzzle of $\chi_{c0}(3915)$
as the conventional charmonium.
