@farhad63,
The issue is that your command is separated onto multiple lines. Put your entire command on a single line like to prevent this issue from occurring.
Alternatively, put a backslash character (\) at the end of each line to let the computer know that your command continues onto the next line. You will note this is what is done in the QIIME 2 documentation — breaking up the command onto multiple lines makes it easier to read in the tutorial, but requires the backslashes to the computer does not think each line is a separate command!
Good luck.