All agents have a expert shopping service that allows you to buy from other platforms, you can basically buy from anyone in China. This is mainly used for buying from Yupoo, WeChat or WhatsApp contacts. Some agents that don't have native Weidian support also require you to use to expert shopping service to buy from Weidian.
It's called expert shopping because the order isn't automatically filled out and processed, you fill out the order info and an agent's employee personally looks after your order.
What agent do you want to buy with?