1) In your SureDone Account, go to Channels>Add Channel (https://app.suredone.com/channels/add)
2) Click on "Add Channel" option for eBay to add a new eBay instance.
3) The new eBay instance will be created as shown below. Next, click on the Authorize eBay button to connect you to eBay.
4) Simply login to your eBay account when prompted.
5) When prompted, click I Agree to authorize the connection between SureDone and eBay.
You will now have a new eBay instance listed under Channels.