I have a qgis project where I have use DataPlotly inside report. Since the last DataPlotly update (4.0.1), I have an error message that appears when I want to export ...
in the meanwhile you can download the zip from https://github.com/ghtmtt/DataPlotly/tree/plotly3 branch and install it in QGIS. It is not ready (yet) to be released as an updated version of the plugin ...