# add these two lines underneath the chunk where you have included the use_python line.
import os
#os.environ['QT_QPA_PLATFORM_PLUGIN_PATH'] = 'C:/ProgramData/Anaconda3/Library/plugins/platforms'
os.environ['QT_QPA_PLATFORM_PLUGIN_PATH'] = 'C:/Users/pptallon/AppData/Local/Anaconda3/Library/plugins/platforms'
library(htmltools)

tags$iframe(src="c:/users/pptallon/desktop/ad/1st_chart.html", width="100%", height="500px")
#includeHTML("c:/users/pptallon/desktop/ad/1st_chart.html")