Synthetic transmission spectra computed with PetitRadtrans and FastChem used as templates for the cross-correlation analysis. They are computed for TOI-1518 b parameters, assuming a temperature of 2500 K. The wavelength coverage of MAROON-X used in this study is represented with blue (blue detector, 490–670 nm) and red (red detector, 640–920 nm) lines. Ions and alkalines have few very strong lines, while other metals are composed of line forests. Molecules also have forests of spectral lines grouped in distinct absorption bands. Except for the Ca+ lines, the other metals present strong signals in the range of the blue detector of MAROON-X, where few telluric lines are present. At 2500 K, the Fe+ and Cr+ lines are smaller than the others and are not visible in this plot.