Spectra at 0.12 (green), 1.41 (orange), and 23 (brown) days after the GRB onset for a homogeneous surrounding medium with v_sa = 13 GHz, v_m = 6 GHz, v_c = 2 × 10⁷ GHz, F_m = 800 μJy, and p = 2.05 at 1 day. Spectrum at 0.12 days: optical observations from Pozanenko et al. (2020) and XRT butterfly plot. Spectrum at 1.41 days: our VLA and MMT detections. Spectrum at 23 days: our 1.5 and 5 GHz observations, optical data from Pozanenko et al. (2020) and the XRT butterfly plot; the optical emission is dominated by the SN component.