Paste the code to you Portfoliobox portfolio’s HTML field.
Next, go to your Portfoliobox portfolio and find the HTML field. It is most likely in the form of an HTML/Code widget or module which you can find on Portfoliobox’s dashboard. Add it to your page, and paste the code you’ve copied before to the HTML field. Save and update, and that’s it, you should have Common Ninja’s Image Slider widget on your Portfoliobox portfolio.