Rights have prices defined for them. Before you proceed, make sure your wallet holds enough of the listed token to purchase the right.
For the right you wish to purchase, click Approve. Approval is letting the rights claiming contract transfer tokens from your wallet. It will only request to approve the specific amount of tokens that the right costs.
Confirm the approval in your web3 wallet.
Once the approval has been mined, click Purchase NFT.
Confirm the transaction in your web3 wallet.
Once the transaction is mined you will see a confirmation message that you own the NFT right.