Sorting layer is a property of SpriteRenderer, it's used to specify which object is at top, and which object is at bottom.
If you want to change the sorting layer in script, you can use following code:
SpriteRenderer sprite = GetComponent<SpriteRenderer>();
sprite_renderer.sortingOrder = ..;
sprite_renderer.sortingLayerName = ..;
We often use following command to start the PHP built-in web server.
php -S localhost:port
But in this way only the machine which starts the server can access it, any other computers cannot access it.
To solve this problem, we can use 0.0.0.0 as the binding IP address
php -S 0.0.0.0:8000
Then other devices are able to access our server as well. Using 0.0.0.0 as the IP addres will make the server bind all available IP addresses on the machine.