Setting up your .csv is the same as setting up any other bulk upload looking as so:
It is just important to note when adding variation items, all your variations should have the same SKU. One of your items should have a GUID that matches the SKU exactly. This item will be known as the parent item. The rest of the GUIDs must differ and are considered the "children".
After setting up your file, go to Products > Bulk Upload and choose the file you want to upload. You must check Skip All Channels to properly add your variation:
You also should make sure Import Media URLs is checked if you are adding images as well. After you have it set up to look like the above, you can click Upload. Your variation items should then be successfully added to SureDone. To list them on your channels, go to the parent variation and list from there. Following these steps exactly will list your variation items successfully.
If you notice that you didn’t check Skip All Channels, the best way to rectify the issue and add your variations correctly is to delete them from SureDone and re-add them making sure you follow the steps outlined in this guide exactly.