Missing write access in mac to /usr/local/lib/node_modules

Run these commands in a terminal window:

sudo chown -R $USER ~/.npm
sudo chown -R $USER /usr/lib/node_modules
sudo chown -R $USER /usr/local/lib/node_modules

from : https://stackoverflow.com/questions/54802330/missing-write-access-in-mac-to-usr-local-lib-node-modules