Now that you've your NFT smart contract, you'll be able to bulk upload your assets.
- Ethereum only supports the upload of 1,000 assets at the same time.
- Polygon only supports the upload of 750 assets at the same time.
If your collection has more than this amount of assets, you'll have to attempt several uploads and pay the correspondent gas fees for each upload.
After bulk uploading your assets, it takes between 2-4 hours to be visible in OpenSea.