0xf305d719?0xf305d719 is the function selector for addLiquidityETH(address,uint256,uint256,uint256,address,uint256). Adds ETH liquidity to a pool.
When a transaction's data begins with 0xf305d719, it is calling addLiquidityETH. The selector is the first four bytes of the keccak-256 hash of the signature addLiquidityETH(address,uint256,uint256,uint256,address,uint256), which is how wallets and explorers work out which function a payload is for.