It's sent by using China Post Ordinary Small Packet Plus which is a cheap service of China Post. China Post doesn't provide tracking service for it after it moves for some stations in China. So, you can't get more update besides the following. Contact the seller to give you a solution if you couldn't get it in time:

2019-06-12 08:53
Arriving at Nanjing International Mail

2019-06-11 19:54
Leave the International Bulk Collection Center, the next stop , Nanjing International

2019-06-11 15:27
International Bulk Collection Center has received