yes, the hash file must contain the username.
1st step you crack the hashes by using the --username switch
2nd step you show the hashes with -m x --show --username original_hash_file_with_usernames.txt (replace x with the same hash type you used in step 1)
if you furthermore want to change the output format, you should read --help for the possible vales of --outfile-format (for instance --outfile-format 1 to "hide" the cracked plain etc)
1st step you crack the hashes by using the --username switch
2nd step you show the hashes with -m x --show --username original_hash_file_with_usernames.txt (replace x with the same hash type you used in step 1)
if you furthermore want to change the output format, you should read --help for the possible vales of --outfile-format (for instance --outfile-format 1 to "hide" the cracked plain etc)