how to charge extra fee for support or modification item

Some days ago I published an wallpaper based android app on CodeCanyon. Yesterday a client asked me that he want to purchase my item but he need modification. He agree to pay extra fee for this modification. but I don’t know how to charge extra fee. My item did not have extra fee option. Does envato allow to me directly receive extra fee from client outside envato.

Hi,
You can request payment via PayPal or bank transfer to client. It is allowed by envato without any involvement. Envato is not liable if your client refuse to payment after work.
Regards

Thanks for quick replay :grinning: