Designer not able to upload pics in Facebook in-app browser

Hi,

I'm using Fancy product designer plugin in my woocommerce/wordpress website. I have enable ads on Facebook to increase my sale. But when user open my website throught facebook app, the website opens in facebook in-app browser. And when users try to customize their products by using FPD, they unable to upload the image. Even pop-up to upload image also doesn't open. This issue appears only in facebook in-app browser. Please fix this issue or let me know how I can fix this issue?

Thanks