Transmission spectrum with model fit solution from model tuning process. Both panels show wavelength (in μm) on the x-axis against transit depth (in %) on the y-axis, as well as the data points and error bars (grey) from the spectrum produced in this work (SP-TW). (Top) Median model solution (solid black line) and corresponding 95% CCI (shaded area). (Bottom) Contributions of individual molecular opacity sources (colour-coded by molecule) and the flat-opacity cloud deck (dashed grey line).