Here is how i installed WebTorrent command line app on the CentOS server.

yum remove nodejs npm -y;yum install nodejs npm -y;npm install webtorrent-cli -g;webtorrent --help

Then i try to download some file:

webtorrent download "magnetlinkreceivedfromWebTorrent-Desktop" --verbose

Then i can seed some file:

cd /home/me/media
webtorrent seed "Video file.mp4"

Then i doubleclick shown "Info hash" and copy it by mouse right click (PuTTy), example Info hash: 463ef7142d1597b12a81f241a273f73fbdc6e9fc

Then i go to the Webtorrent Desktop software on my Windows computer, click File / Open Torrent Address...
And paste info hash. Download start immediately.

So far im unsure how to obtain magnet link from webtorrent-cli, but it can be obtained from Webtorrent Desktop.