Distributions of the empirical Monte Carlo analysis for the 12 Å passband on the Na I doublet (top panels) and 10 Å on Hα (bottom panels), for each of the ESPRESSO transits. The results from the first and second night are displayed in the left and right panels, respectively. The distributions representing the in-in (red bins) and out-out (blue bins) scenarios are centred at zero, corresponding to non-detections, as expected. The in-out distributions (black bins) for Na I and Hα deviate from zero in both transits, indicating a detection of planetary origin. The Gaussian fits to the histograms are shown as dashed lines of the respective colour.