Are you the buyer?
You don't.
Especially with low priced goods sellers often do not make you pay for expensive tracking which only protects the seller* not you.
It's really not useful or a problem.
If your seller is in Europe it should take about 15 days to arrive.
If your seller is in the USA it should take about 20 days to arrive.
If your seller is in Asia it should take about 30 days to arrive. (If that seller tells you it will take longer, be suspicious. If he promises a replacement,he is scamming you.)
If an item has not arrived within 30 days after the estimated date of arrival, you go to the Resolution Centre at the bottom of this page and open an Item Not Received dispute.
If the seller cannot prove delivery, you will be refunded.
*Same with insurance. You are paying for something that protects only the seller.
