Switch to the network on which you want to add an asset via the icon on the top left of the screen. With Bridge Wallet, you can add assets on Arbitrum, Avalanche, BNB Chain, Base, Ethereum, Fantom, Gnosis Chain, Optimism, Polygon, Rootstock, Tezos and zkSync Era.
Click on "Add an asset" in the Assets tab or "Add a currency" in the Currencies tab. You are free to choose in which tab you want to add a token.
Type the name of the token in the search bar, or paste its contract address that you can find on the block explorer of the blockchain you're on:
You will now see the token appear in your wallet with your current balance. You can now use Bridge Wallet to send, receive and exchange that token from your phone.
You can remove tokens that you have manually added at any time.