To sell an NFT, you have to open your profile. Then, click on your connected wallet address in the top right corner, revealing your profile, as shown in the image below.
In your profile, click on the OWNED category.
Within the OWNED category, browse and select the NFT you want to sell. You should see a LIST NOW button just like the image below. Click on LIST NOW and input your listing Price.
After providing your listing price, Click on List NOW. Your wallet will pop up asking you to approve the transaction.
To learn more about your profile section, click here