Top panel: [O I] λλ6300, 6364 doublet region for the last three nebular spectra of ASASSN-20jq are plotted in velocity domain with respect to 6300 Å. The pair of black dashed lines represent the rest position of the [O I] doublet lines λλ6300, 6364, while the dashed red lines represent the [O I] doublet redshifted by ≈2200 km s⁻¹. Bottom panel: Pseudo-continuum subtracted [O I] λλ6300, 6364 doublet region of the +229 d spectrum. A two-component Gaussian profile is fitted with FWHM constrained to be the same. The flux ratio of the doublet components L₆₃₀₀/L₆₃₆₄ is estimated to be ≈1.67 and the FWHM for each component is ≈1900 km s⁻¹.