http://track-chinapost.com/result_china.php?order_no=LZ434808910CN shows No shipping record. Your seller applied this tracking number from china post but never actually ship anything to you. You are very likely to be scammed.

if you just got this number, You should push seller to ship the goods immediately. Tell him if you can not track real shipment data in next 3 days, you will open dispute to aliexpress/amazon/ebay/paypal against fraud.

if you have got this number for long time and paid with paypal/aliexpress/WISH/AMAZON, you need open dispute immediately against fraud and claim refund.