Can't add time to my X axis on my Plotly/Dash chart

I’m creating a Dash webapp where i have a real-time plotly chart. This chart gets updated every second. I would like to add to my X axis time instead of a fixed value. I tried setting tickvals= to dt.now but it doesn’t work, since tickvals needs an array. Any advice?

 def gen_wind_speed(interval):
    	
    	trace = Scatter(
    		y=df['num'],
    		line=Line(
    			color='#42C4F7'
    
    		),
    	)
    
    	layout = Layout(
    		height=450,
    		xaxis=dict(
    			showgrid=False,
    			showline=False,
    			zeroline=False,
    			fixedrange=True,
    			tickvals= dt.now 
    			
    		),
    		
    		margin=Margin(
    			t=45,
    			l=50,
    			r=50
    		)
    	)
    
    	return Figure(data=[trace], layout=layout)