From the README in the git repository:
In most cases, you are safer using the Dash HTML component classes, dash-html-components (GitHub - plotly/dash-html-components: OBSOLETE - now part of https://github.com/plotly/dash). You can also provide HTML in a sandboxed iframe using the dash_html_components.IFrame(srcDoc=‘raw html here’) component, see Rendering HTML similar to Markdown - #2 by chriddyp
Have you tried this?