Docker run --rm inputoutput/cardano-wallet serve -testnet <file> shows file not found error

Failed to parse Byron genesis configuration. You may want to check the filepath given via --genesis and make sure it points to a valid JSOn byron genesis file. The genesis file must be Byron, not Shelley as it used to feed the wallet with the initial blockchain parameters. Here’s perhaps some helpful hint: GnesisDataIOError OpenBinaryFile: does not exist )No such file or directory)
Could you please help me to run wallet server in ubuntu 20?