Issue with using REST API – 402 Error

That error is returned by your site when WordPress.com tries to query your site for data.

To find out more about what could create that error, could you add the following to your site’s wp-config.php file?

define('WP_DEBUG', true);

if ( WP_DEBUG ) {

        @error_reporting( E_ALL );
        @ini_set( 'log_errors', true );
        @ini_set( 'log_errors_max_len', '0' );

        define( 'WP_DEBUG_LOG', true );
        define('WP_DEBUG_DISPLAY', false);
        define( 'CONCATENATE_SCRIPTS', false );
        define( 'SAVEQUERIES', true );

}

Once you’ve done so, try loading the API again, and then check the wp-content/debug.log file for errors. You can paste the results here.

You can then replace define('WP_DEBUG', true); by define('WP_DEBUG', false); in the code above.

If no errors are returned in your logs, it’s most likely that the error is returned by your hosting provider; it could be caused by security rules or a firewall for example.

Let me know how it goes.