Bar chart graph, with multi select line and drop down. How to update it?

Hi, I dont know if this is a dash or a plotly q.

I need to do a bar chart, that has a multi select line
the multi is for the x axis, and the bar chart should be able to plot varius params.

the y axis should be the count

I have to wrap this with a call back, that should define and return a chart

Dont really know how to make all this.

It should look something like this:

@app.callback(Output('graph4', 'figure'), [Input('multi_select_line_chart1', 'value')])
def update_bar(df.columns[0]):
    
    for VPIP in df.columns[0]:
        chart4.add_trace(px.bar(x=df.columns[0], y=df[VPIP],
                                mode="lines", name=VPIP))


    chart4.update_layout(
                         xaxis_title=df.colums[0],
                         yaxis_title=df[VPIP],
                         title="Apple Stock Prices [Apr-2019-Mar-2020]",
                         height=500,)
    
    
    return chart4

Please help.