The "Insufficient Balance" warning occurs when your wallet doesn't have enough ETH to register a name.
Check these:
Your connected wallet is correct
You have ETH on Ethereum Mainnet (not L2s like Base, Arbitrum etc)
You have extra ETH to cover gas price fluctuations and any added profile records during registration.
Solution: Top up your wallet with more ETH on Ethereum Mainnet.
Registration, renewal and gas fees must be paid in ETH on mainnet.