Low-resolution spectrum observed with ALFOSC. The telluric-free optical spectrum of TOI-519 is shown in red (spectral resolution of 16 Å), and a solar-metallicity M4.0 spectral standard template from Kesseli et al. (2017) is plotted as the grey line (this spectrum has been degraded to the resolution of our target and it is also corrected for the telluric lines absorption). The most significant spectral features are labelled. The spectra are normalised to unity at around 7500 Å.