Clone this project into your Wordpress project
/wp-content/themes/
Rename folder name to fit your needs.
Go to Settings -> Headless Mode in WP Dashboard and configure wp-config.php file.
Add the following to your wp-config.php file to redirect all traffic to the new front end of the site (change the URL before saving!):
define( 'HEADLESS_MODE_CLIENT_URL', 'https://example.com' );
If after saving the wp-config.php file, your site is still not redirecting, make sure you've replaced https://example.com above with your front end web address.
Check functions.php with for a example custom endpoint you can build.