If a tracking number is missing or incorrect on an order,
Paste the Easync order link into the chat
my.easync.io/stores/.../orders/...
and note what needs fixing (missing tracking, or the correct tracking number/details if you have them).
Send a separate link for each affected order.
Support adds or corrects the tracking on their end and will reply "Tracking provided" once it's done.
Keep in mind that after the tracking is updated in Easync, it can take up to 24 hours for the corrected status to sync through to eBay, so a short delay before it appears on the marketplace is normal.