[Tutorial] blog module building error

when I try this tutorial, something wrong with starport relayer configure command

here is the message of error

% starport relayer configure -a \
--source-rpc "" \
--source-faucet "" \
--source-port "blog" \
--source-version "blog-1" \
--source-gasprice "0.0000025stake" \
--source-prefix "cosmos" \
--target-rpc "" \
--target-faucet "" \
--target-port "blog" \
--target-version "blog-1" \
--target-gasprice "0.0000025stake" \
--target-prefix "cosmos"

Setting up chains

cannot resolve source: could not setup chain: Error: must provide a non-empty value

I tried to follow the tutorial, but I got this message: "I don’t know what value means, so I’d like to ask you a question.

starport version is v0.16.2
The earth/mars chain is successfully launched and no errors are found in the code that I modified as instructed.