Comparison between observed and synthetic transmission spectra in the region covered by the STIS data. Top: mid-resolution (≈9 Å binning) STIS transmission spectrum is shown with red points. Bottom: low-resolution (≈74 Å binning) STIS and UVIS transmission spectra are shown with the red circles and green triangles, respectively. In both panels, the blue and black lines show the LTE and NLTE synthetic transmission spectra, respectively, while the grey horizontal dashed line indicates the broad-band R_p/R_s obtained from the EulerCAM optical transits (Hellier et al. 2019). The horizontal error bars shown for the red and green points correspond to the size of the wavelength bins.