0x87087623?0x87087623 is the function selector for bridgeERC20(address,address,uint256,uint32,bytes). Bridges tokens to another chain.
When a transaction's data begins with 0x87087623, it is calling bridgeERC20. The selector is the first four bytes of the keccak-256 hash of the signature bridgeERC20(address,address,uint256,uint32,bytes), which is how wallets and explorers work out which function a payload is for.