remove old version of node and install new
First remove previous version
$ sudo apt remove nodejs
Installing Node.js with Apt Using a NodeSource PPA
cd ~
curl -sL https://deb.nodesource.com/setup_16.x -o nodesource_setup.sh
Inspect the contents of the downloaded script with nano (or your preferred text editor):
nano nodesource_setup.sh
When you are satisfied that the script is safe to run, exit your editor, then run the script with sudo
sudo bash nodesource_setup.sh
The PPA will be added to your configuration and your local package cache will be updated automatically. You can now install the Node.js package in the same way you did in the previous section:
sudo apt install nodejs
Verify that you’ve installed the new version by running node with the -v version flag:
node -v