Here are the steps to connect Core to OpenSea.
Avalanche is unique in that you can have NFTs on the X-Chain and the C-chain. Wallets such as Core and Metamask utilize the C-chain for NFTs.
1. Navigate to https://opensea.io/, and locate the wallet icon in the upper right-hand corner.
2. Click the wallet icon, and select "Core" from the list of wallets.
3. Click, "Approve" to connect the wallet to Core.
4. After successfully connecting Core to OpenSea, the total wallet balance will be displayed along with the tokens that are available.
5. To view Avalanche C-Chain NFT's in the Core wallet on OpenSea, hover over the profile circle in the top-right, and click "Profile."
6. Avalanche C-chain NFT's will be displayed, and can be easily sorted with the tools available in OpenSea.
7. To sell an Avalanche C-chain NFT on OpenSea, click on the specific NFT to access the option to list it on the marketplace.
8. Click, "Sell" to list the Avalanche C-chain NFT, and then input the specific sale terms. Multiple options are available to customize, and then click, "Complete Listing."