Projection of TOI-858 B in the plane of sky for the best-fit orbital architecture. The black arrow shows the sky-projected stellar spin. The stellar disc is coloured as a function of its surface RV field. The normal to the orbital plane of TOI-858 B b is shown as a green arrow. The thick green solid curve represents the best-fit orbital trajectory. The thin lines surrounding it show orbits obtained for orbital inclination, semi-major axis, and sky-projected obliquity values drawn randomly within 1σ from their probability distributions. The star, planet (black disc), and orbits are to scale.