Follow the below steps to install and set up PWA in 2.3 :

Prerequisite :
You must have a version of  NodeJS >=10.14.1 , and Yarn > = 1.13.0. I suggest using the Latest versions of both are recommended.

1 ) Use the following command :

/var/www/html/m23 is a Magento installation directory.

2 ) Install Magento by Command Line:

While you have completed with Magento installation, Now
3 ) Now clone pwa-studio repository :

I have cloned this repository in magento root directory ex: /var/www/html/m23
4 ) You will see the pwa-studio directory in /var/www/html/m23.
Enter into this directory :

5 ) Run :

6 ) Specify the Magento backend server in .env file. you can see the .env.dist file in
/var/www/html/m23/pwa-studio/packages/venia-concept/ direcoty. If you are not
able see, enable show hidden files. Now create .env file from this env.dist

7 ) Open this .env file and find MAGENTO_BACKEND_URL. Here configure your
local Magento 2.3 instance, my case it is :

7.1 Generate SSL certificate because PWA features require an HTTPS Secure Domain. From the root directory of PWA (/PWA-studio) run the below command:

Note: 7.1 Feature requires administrative access.

8 ) Now let’s install sample data for venia-theme to make it good-looking.

9 ) Run the following command in the Magento root directory setup the repository for the sample data in https://repo.magento.com: composer config –no-interaction –ansi repositories.venia-sample-data composer https://repo.magento.com

9 )  Require in the sample data :

10 ) Now go back to pwa-studio directory /var/www/html/m23/pwa-studio and start Server.

The above command maybe gives the permission error, so run the below command with sudo.

12 ) Run the server, Use any of the following commands from the project root directory to start the server:

Last steps to run the following commands :

You are Done! 🙂