On each sold item in 'Orders' there should be a dropdown menu where you can add the tracking.
If you printed and used Ebay's Simple Delivery labels, then the tracking is added automatically and the item is marked as sent when scanned by Evri or Royal Mail.
If the items sold with Simple Delivery but you didn't use those labels, the tracking won't update and you will have to wait 14 days for payment unless you manually update the tracking.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)