Plotly chart studio fitting data with errors


Looking at some past tutorials, I see that there were options to fit data (with errors) and get out fit parameters and errors on the fit parameters on chart studio. (please see the YouTube video that is linked from the tutorials from Plotly website)

I am not able to get any fit results (beyond the value of the fit parameters) and the fit does not seem to take into account the error on the parameters. Is this no longer supported?

Thank you,