Optical and NIR spectra of AT 2018bwo, corrected for the redshift (z = 0.001558) and for the reddening (E(B − V)_MW = 0.02 mag). Top panel: full wavelength range. Bottom panel: close-up view of the spectral set in the optical domain. The instrumental configurations and the phases from the earliest detection are also reported. We remark that the epoch of the outburst onset adopted in Sect. 4 was 40 days earlier.