Well, after uninstalling these packages I did this way and worked:
Installed wget command
sudo apt install wget
Installing nvm using wget
wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
Allowing nvm being used by my profile
source ~/.profile
list the nodejs available versions
nvm ls-remote
Installed the latest one
nvm install v.14.2.0
Installed grunt-cli globally with:
npm install -g grunt-cli
Installed grunt in the project folder
npm install grunt --save-dev
I was still having permission issues with grunt, so:
sudo chown -R username ./*
Now grunt ors_local worked.
I’m not sure if all of this is necessary, since I fetched it from random tutorials on the internet, but that was a solution.
Best regards.