after the TDE has completely faded will be required to confirm whether this galaxy is also a member of this class.

Galaxy emission lines and evidence for an AGN {#sec:bpt}
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The metallicity preferred by <span style="font-variant:small-caps;">prospector</span> would be very low for a galaxy of $\gtrsim10^{10}$, though @vanVelzen2020 find similarly low metallicities for all TDE hosts in their sample, including AT2019qiz, from their SED fits. Spectroscopic line ratios provide a more reliable way to measure metallicity. The TDE spectra clearly show narrow lines from the host galaxy. We measure the fluxes of diagnostic narrow lines using Gaussian fits. Specifically, we measure H$\alpha$, H$\beta$, \[O III\]$\lambda5007$, \[O I\]$\lambda6300$, \[N II\]$\lambda6584$, and \[S II\]$\lambda\lambda6717,6731$. We report the mean of each of these ratios (averaged over the six X-shooter spectra) in Table \[tab:bpt\]. No significant time evolution is seen in the narrow line fluxes. To estimate the metallicity, we use the N2 metallicity scale (\[N II\]$\lambda6584$/H$\alpha$), adopting the calibration from @Pettini2004, to find an oxygen abundance $12+\log({\rm O/H})=8.76\pm0.14$. This corresponds to a metallicity $Z/Z_\odot=1.17$, more in keeping with a typical massive galaxy. However, this \[N II\]$\lambda6584$/H$\alpha$ ratio is outside the range used to calibrate the @Pettini2004 relation, so this metallicity may not be 