Great question. You do not need a Coinbase account to add Solana to your Phantom Wallet. You can add Solana directly from your Phantom Wallet by using the MoonPay option within the Phantom Wallet. MoonPay allows you to buy Solana directly from your Phantom Wallet account using a credit/debit card. It is a fast process, and you can read our blog post below that has a step-by-step guide on how to add Solana through the MoonPay option on your Phantom Wallet.