Geom_smooth LEGEND disappears on PLOTLY

it seems PLOTLY is ignoring the LEGEND when I use geom_smooth. If I use geom_point it shows but I do not want a geom_point. ggplot shows the legend even if i dont use a geom_point() but plotly ONLY shows a legend if I use geom_point. I would like to use only geom_smooth and plotly to show the pegend based on the color.

p_gg <- ggplot(data=test2, aes(x = DT_STAY_DATE, y = OCCUPANCY,colour=PROPERTY_NAME)) + geom_smooth(method = “gam”, formula = y ~ s(x,bs=“cc”,k=12)) —> I SEE THE LEGEND ON THE RIGHT

However, when I do ggplot_ly(p_gg)…—>LEGEND DISAPPEARS

I want to know why PLOTLY removes the GGPLOT legend.