Metallicity measurements for the environment around SN 2021adxl using the VLT/X-shooter spectrum on 2023 February 26 (+480d). The histograms are measured metallicities for hosts of Type IIn SNe (Habergham et al. 2014; Moriya et al. 2023), Type II SLSNe (Leloudas et al. 2015), and both Type I and II SLSNe (Perley et al. 2016) using various methods, denoted in the legend, and detailed in Sect. 3. The vertical lines mark measured values for SN 2021adxl using different methods (see text). We also mark the reported metallicity for SN 2010jl at Z ≈ 0.32 Z_⊙ (Stoll et al. 2011) and for SN 2013L at Z ≈ 0.30 Z_⊙ (Taddia et al. 2020).