Can you add Solana to MetaMask?
Solana is not EVM-compatible. MetaMask supports it only through a separate Solana account type in newer versions, not by adding a custom network.
Why it does not work
Solana uses its own runtime and ed25519 addresses. There is no chain ID or EVM JSON-RPC endpoint to point MetaMask at.
Search results promising a “Solana RPC for MetaMask” are either describing a bridged wrapper token on an EVM chain, or they are simply wrong. There is no setting to change.
What to use instead
If you already sent funds to the wrong address
Funds sent across incompatible networks are generally unrecoverable, because no one holds the key to that address on that chain. The one exception is a deposit to an exchange: exchanges sometimes recover wrong-network deposits for a fee, so open a support ticket with the transaction hash before doing anything else. Anyone who contacts you offering to “recover” it for an upfront payment is running a scam.