When minting an item on OpenSea using our Create button, you won’t be able to bulk upload.
You’ll see a reCAPTCHA verification each time you upload an item. This helps keep OpenSea a secure and spam-free marketplace.
You can bulk upload items using a custom smart contract; however, we're not able to help troubleshoot at this time. Check out our documentation for developers here.
Our reCAPTCHA looks like this: