Problem with update npm for nodejs extension

Hello, I call update npm for nodejs extension (02 - How to install npm & manage npm versions | npm Documentation)
# /opt/plesk/node/8/bin/npm install npm@latest -g

After this I get now for
# /opt/plesk/node/8/bin/npm -v
this line
/usr/bin/env: node: No such file or directory

I have remove and install nodejs extension in plesk gui again, but that not fix it. How I can repair it?

Version 6+7 is working fine:
# /opt/plesk/node/7/bin/npm -v
4.0.5