The official website for Node.js is https://nodejs.org/en/
Go to the page and download the package
Installing Node.js with Apt from the Default Repositories
Ubuntu 20.04 contains a version of Node.js in its default repositories that can be used to provide a consistent experience across multiple systems. At the time of writing, the version in the repositories is 10.19. This will not be the latest version, but it should be stable and sufficient for quick experimentation with the language.
To get this version, you can use the apt package manager. Refresh your local package index first:
sudo apt update
sudo apt install nodejs
Check that the install was successful by querying node for its version number:
$ node -v > v10.19.0
If the package in the repositories suits your needs, this is all you need to do to get set up with Node.js. In most cases, you’ll also want to also install npm, the Node.js package manager. You can do this by installing the npm package with apt:
$ sudo apt install npm
This allows you to install modules and packages to use with Node.js.
At this point, you have successfully installed Node.js and npm using apt and the default Ubuntu software repositories. The next section will show how to use an alternate repository to install different versions of Node.js.
For users in China, please add the following mirror settings to make sure your
npm running as expected
npm config set registry https://registry.npmirror.com