Measurements of $R(D^{(*)})$ and other missing energy decays at Belle II

The Belle II experiment and SuperKEKB energy-asymmetric $e^+e^-$ collider have already successfully completed Phase 1 and 2 of commissioning with first collisions seen in April 2018. The design luminosity of SuperKEKB is $8\times10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than the Belle experiment. With this much data, decays sensitive to physics beyond the Standard Model can be studied with unprecedented precision. We present prospects for studying lepton flavor non-universality in $B\rightarrow D^{(\ast)}\tau\nu$ modes. Prospects for other missing energy modes sensitive to physics beyond the Standard Model such as $B^+\rightarrow\tau^+\nu$ and $B\rightarrow K^{(\ast)}\nu\overline{\nu}$ are also discussed.