How to render Google chart pdf file using wicked pdf rails 4?

Application setup is rails 4 & wicked pdf. how to render pie chart using google chart in my pdf file?

I found solution on this at https://github.com/barryvdh/laravel-snappy/issues/255#issuecomment-645453114

I think you need to tell wkhtmltopdf to wait for you to be ready.