You can purchase Bitcoin (BTC) directly using the Phantom wallet.
First, open the Phantom application and click the "Buy" button. Select the Bitcoin token and specify how much you'd like to purchase. Phantom's partnerships with MoonPay, PayPal, Coinbase Pay, and Robinhood enable you to make your purchase without visiting an exchange directly.
At present, you can purchase Bitcoin via Taproot only through MoonPay. However, if you prefer Native SegWit, you have options like Coinbase Pay, Robinhood, PayPal, and MoonPay.
After selecting a provider, a pop-up window will appear for you to log in or create an account to complete your purchase.
If you encounter any issues, reach out to the provider's support team. Alternatively, you can also buy Bitcoin from various exchanges and deposit them into your Phantom wallet