Custom CSS styling can't apply when downloading PNG

[ghnmqdtg]

Hi! Recently I've been developed an analysis app for scientific research with Apexchart to plot some raw data.

In this project, I create custom charts with Apexchart options and CSS files, such as font-family(Roboto), tooltip title colour, tooltip marker radius, and width of legends. Everything looks great as I expected it to be in my app. But, when I download charts as PNG files, all the custom stylings run unavailable.

I also tried using html2canvas to output the chart image to PDF file by jsPDF, but still got the same issue. Is there any idea or suggestion for me?

• Inside my app
  

• Output image
  

[matinwd]

Having Same issue. Any ideas?