Hello @Seller_lSmS3ZARapxTU,

Michelle at Amazon here. It depends on the file you are using which attribute you need to add to the file, for example, for the parent variation, you would just need ensure that you use the valid value for that specific file. If you are just looking at the size column, then it's just asking for the size. If you have specific questions on your file, please reach out to Seller Support with the category for your template that you are using, the columns you are looking at and any ASIN's you are trying to variate. They can then look into this for you deeper. You may also find this post on variations helpful as well.

If you need further assistance, please provide me with the case ID and I would be happy to look into this further for you.

Wishing you the best!

Michelle