At the first check your Matic balance You will need it for gas fee(0.03-0.05$)
On the main page click to "Open Marketplace"
Click to SIGN IN
Connect via MetaMask or any other web3 wallet
Click to profile to change the information
Click to Create and fill the information of your NFT
Click to MY ITEMS to check NFT and put it for the sale
Go to your profile and click to LOGOUT
Now you can check your NFT and price for which you are selling