For making this cleared, with this case, you should follow this instruction so when you got order placed, the tracking code number will be sent to your customer.
Go to Ali Orders Dashboard > Orders List > Orders Setting
Make sure, the box "Send notification email to customers about the order fulfillment" is checked.
Then you can simply save settings.
When you got new orders placed again, it will be sent to your customer automatically.
Please let me know if you need some more help.