Best fit of the GRB 191004B Lyα line, observed in the X-shooter host-galaxy spectrum, with unconstrained shell models. Top panel: the solid black line corresponds to the data with their error bars (grey), in dashed orange the best fit and in dotted blue the intrinsic Lyα emission predicted by the model. In the top left corner, we show the best-fit parameters. Bottom panel: the dots correspond to the normalized residuals between the observation and the model. The orange ones are for the Lyα profile only with the corresponding p-value for the Shapiro-Wilk test.