Phase-resolved 2D transmission spectra based on the combination of three nights around the Hα line without and with RM+CLV correction applied in the left panel. The horizontal black-dashed lines indicate the beginning and end of the transit. The inclined black-dashed line presents the expected trace of signal from the exoplanet atmosphere. The in-transit part of this line is not plotted so as not to interfere with the visibility of the trace signal. The middle panel shows the 2D transmission spectra in the planetary rest frame (PRF) assuming K_p = 159.76 km s⁻¹, and the vertical black-dashed lines indicate the position of expected signal from the exoplanet atmosphere in the PRF. The right panel shows the combined integrated transmission spectrum of Hα. The grey line represents the transmission spectra in the PRF that has been corrected for the CLV+RM effects, the black dotted line is the binned version with a bin size 0.1 Å, while the best Gaussian fit of the Hα line is shown in red. The dashed green vertical line represents the static position of Hα at vacuum wavelength.