If you can't add the tracking to the case, then contact Ebay Customer Services using the link below and get them to add the tracking.
Usually, if you use a QR code, the tracking is automatically added when the code is scanned. Obviously this has not happened.
ttps://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
"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)