Unable to complete TLS handshake: Unable to set private key file

[kailas-insnapsys]

I'm trying to access with WSS. Set certificate & private key file path in .env file. but getting below error

UnexpectedValueException {#1506
  #message: "Unable to complete TLS handshake: Unable to set private key file `/var/www/html/storage/ssl/private.key'"
  #code: 0
  #file: "./vendor/react/socket/src/StreamEncryption.php"
  #line: 133
  trace: {
    ./vendor/react/socket/src/StreamEncryption.php:133 { …}
    ./vendor/react/socket/src/StreamEncryption.php:76 { …}
    ./vendor/react/event-loop/src/StreamSelectLoop.php:245 { …}
    ./vendor/react/event-loop/src/StreamSelectLoop.php:212 { …}
    ./vendor/cboden/ratchet/src/Ratchet/Server/IoServer.php:74 { …}
    ./vendor/beyondcode/laravel-websockets/src/Console/StartWebSocketServer.php:155 { …}
    ./vendor/beyondcode/laravel-websockets/src/Console/StartWebSocketServer.php:52 { …}
    ./vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:36 { …}
    ./vendor/laravel/framework/src/Illuminate/Container/Util.php:40 { …}
    ./vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:93 { …}
    ./vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:37 { …}
    ./vendor/laravel/framework/src/Illuminate/Container/Container.php:596 { …}
    ./vendor/laravel/framework/src/Illuminate/Console/Command.php:136 { …}
    ./vendor/symfony/console/Command/Command.php:258 { …}
    ./vendor/laravel/framework/src/Illuminate/Console/Command.php:121 { …}
    ./vendor/symfony/console/Application.php:920 { …}
    ./vendor/symfony/console/Application.php:266 { …}
    ./vendor/symfony/console/Application.php:142 { …}
    ./vendor/laravel/framework/src/Illuminate/Console/Application.php:93 { …}
    ./vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php:129 { …}
    ./artisan:37 {
      ›     $input = new Symfony\Component\Console\Input\ArgvInput,
      ›     new Symfony\Component\Console\Output\ConsoleOutput
      › );
      arguments: {
        $input: Symfony\Component\Console\Input\ArgvInput {#27 …}
        $output: Symfony\Component\Console\Output\ConsoleOutput {#25 …}
      }
    }
  }
}

we already have added a private key path with correct permissions, but it still shows this when the web socket client tries to connect to the web socket server.