Normalised NIRPS spectrum of TOI-672 (black line) compared to PHOENIX ACES stellar models (coloured lines). The models are described in Section 3.1.1. Top row : models with a fixed metallicity of −0.3 dex and T_eff values of 3720 (blue), 3820 (orange), and 3920 (green) K for two spectral regions. Bottom row: same regions, but we show models with a fixed T_eff of 3820 K and metallicity values of −0.5 (red), −0.3 (purple), and −0.1 (brown) dex. For strong spectral lines, we performed χ² minimisation between the NIRPS spectrum and a grid of PHOENIX ACES models, finding T_eff = 3810 ± 33 K and [M/H]=−0.3 ± 0.1 dex.