Left Panel: Example of probability distribution functions (PDFs) from the data and the fiducial model at redshift z = 5.4. The blue line shows the histogram obtained from the data, while the dashed black line shows the fit using Gaussian KDE. Similarly, the red line shows the distribution obtained from our fiducial model. For the likelihood analysis, we use 15 equally spaced bins as marked by the black solid points. Right Panel: Normalized covariance matrix at z = 5.4.