Phantom has recently added support for Ethereum and Polygon networks. Until Phantom is supported more widely, select [fox] Metamask from the Connect Wallet dialog to connect with the Phantom Multi-chain Beta. We anticipate our own connect option to roll out to most dapps over the coming months.
If you have MetaMask already installed, you may need to move Phantom to a different browser entirely for optimal experience as last wallet installed becomes the default. Learn more here.