Install nodejs v20 on Debian and Ubuntu based distributions

step 1 : Download and import the Nodesource GPG key

sudo apt-get update
sudo apt-get install -y ca-certificates curl gnupg
sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg

step 2 : Create deb repository

NODE_MAJOR=20
echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list

optional: here we are installing nodejs v20 but if you want to install v18 change NODE_MAJOR=18 in above command. Similarly if you want to install nodejs v16 then change NODE_MAJOR=16.

step 3 : Run Update and Install

sudo apt-get update
sudo apt-get install nodejs -y

congratulations you just installed nodejs

To uninstall nodejs

sudo apt-get purge nodejs &&\
rm -r /etc/apt/sources.list.d/nodesource.list &&\
rm -r /etc/apt/keyrings/nodesource.gpg

1. INSTALL (Node Version Manager) be following command:

   curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

2. Now, reopen your terminal, or "exit" command if you server ssh and reconnect

3. Get packages by following command:

   nvm install 20

4. Veryfiy node by:

   node -v # should print v20.16.0

5. Finally check the npm:

npm -v # should print '10.8.1'

Gongrates! You have done!

Following this github comment, just run nvm list available and then nvm install x.y.z

Don't forget to nvm use x.y.z after you're done. I used this manual - in case it helps.

Looking at the warning which you added in your question, I surmise that nvm is installed on your machine but may not have been setup properly. Nevertheless, adding full steps for you to verify which one you missed and fix the same.

1. Confirm nvm is installed

Before making changes, check if nvm exists:

# confirm nvm is installed
$ brew list | grep nvm
# if the above doesn't return anything, install nvm
$ brew install nvm

2. Ensure your system is in good shape

Sometimes Homebrew issues prevent nvm from working properly. For that run:

$ brew doctor
# If you see any warnings, follow the suggested fixes and 
# rerun brew doctor until everything looks good. 

3. Create the nvm directory (if missing)

$ mkdir -p ~/.nvm

4. Add nvm to your shell configuration

Manually add these lines to ~/.zshrc:

export NVM_DIR="$HOME/.nvm"
[ -s "$(brew --prefix nvm)/nvm.sh" ] && . "$(brew --prefix nvm)/nvm.sh"
[ -s "$(brew --prefix nvm)/etc/bash_completion.d/nvm" ] && . "$(brew --prefix nvm)/etc/bash_completion.d/nvm"

Save the file and reload the configuration:

$ source ~/.zshrc

5. Verify and Restart

Check if nvm is now working:

$ nvm -v

If you still get an error, restart your terminal and try again. Sometimes failing to do this might also lead to issues.

it wasn't an issue while i was trying to install node 12.X.X but below that it was a big pain so i followed below steps and it worked for me

Uninstalled nvm if it’s already installed using Homebrew.

brew uninstall nvm
brew cleanup

Install Rosetta

softwareupdate --install-rosetta

Make terminal/iTerm2 to open in Rosetta mode

got to Application (-> utilities) -> right click on terminal app -> get Info -> Select "Open using Rosetta" -> Restart Terminal

In Terminal run a command

arch -x86_64 zsh 

Make sure machine has .zshrc file if not just create one

cd ~
touch .zshrc

Install NVM

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash

Restart the terminal and check if nvm is installed successfully by running

nvm -v

Then install Node with nvm as usual

nvm install 10