Appending/Extending plots

This might be a silly question but I’m super new to python and anvil but I was wondering how to append or extend traces onto an existing plot. I’m using Plotly so I checked this https://plotly.com/python/horizontal-bar-charts/#basic-horizontal-bar-chart-with-plotly-express
but it seems to be a different version or plotly in anvil? or it might be because I’ve got the free version of anvil.
Basically, I want to recreate those horizontal ‘stacked’ bar charts on that site. Is there a way to change the layout of a plotly bar in anvil too?
I’ve also checked the docs regarding plot functions but the ‘append_traces’ seems quite vague, not sure what parameters to pass in. :confused:

Thanks in advance
Kat