Bought my own tracking

[thebarrelman]

I open a return case and the seller accepted to refund me. The thing is I don’t have printer ink and it’ll cost me 70 bucks to buy one so instead I went to the post office and purchased my own tracking number and mailed the item back to them. So how do I tell EBay the tracking number I have to let them know the item has been sent? A little help appreciated thanks