When creating variants individually, the process can become complicated because Etsy doesn’t have a native resource for managing variants. This becomes especially problematic when you have multiple variants, each with several options.

We highly recommend using our "bulk create/update product variants" resource, as it helps prevent any issues related to managing variant options, thus reducing the risk of errors when creating the variants.

IMPORTANT NOTE:
This resource will overwrite all variants of a product, so you must provide all the variants you want for that product. Variants that were previously created but are not included in the payload will be lost.