The Belle II experiment has accumulated data corresponding to $213~{\rm fb}^{-1}$ of integrated luminosity at the SuperKEKB asymmetrc-energy $e^+e^-$ accelerator and is performing well. While the data are being collected toward the final goal of $50~{\rm ab}^{-1}$, which will allow searching for rare processes and high precision in spectroscopy, the current data already allow for performing analyses.

We present here the analysis of $B\to KJ/\psi\pi^+\pi^-$ decays using a $\Upsilon(4S)$ data sample of $62.8~{\rm fb}^{-1}$. We find an evidence for a $X(3872)$ signal at a statistical significance of $4.6\sigma$ and confirm that the obtained branching fraction of $B\to K\psi(2S)$ agrees with the world average. When larger sample will be available, Belle II plans an even more interesting analysis of $B\to D\bar{D}\pi^0K$, where $X(3872)$ is reconstructed in the $D\bar{D}\pi^0$ channel in a pursuit for the natural width measurement.