I'm getting this error after typing your mentioned command.

Here:-

root@kali:~# wget -q -O https://archive.kali.org/archive-key.asc | apt-key add
wget: missing URL
Usage: wget [OPTION]... [URL]...

Try `wget --help' for more options.
gpg: no valid OpenPGP data found.
root@kali:~#

I've no clue how to fix this, I'm new to kali-linux.