Note, there are two kind of ARM processors: arm64 or armv71 (32 bit)
myVers =20.9 #set your desired version here
sudo apt-get uninstall nodejs
wget "https://nodejs.org/dist/v${myVers}.0/node-v${myVers}.0-linux-arm64.tar.gz"
tar -xvf "node-v${myVers}.0-linux-arm64.tar.gz"
sudo cp "node-v${myVers}.0-linux-arm64" "/etc/node${myVers}" -r
sudo ln -s "/etc/node${myVers}/bin/node" /usr/bin/node
sudo ln -s "/etc/node${myVers}/bin/npm" /usr/bin/npm
node --version
That way, npm and node will be system-wide available.