How I can create System.Guid in Unity?

So basiclly i need somehow to create Guid but Unity doesn’t creating it.

code looks like this:

private Guid _id;
 
private void Awake()
{
    _id = new Guid();
}

and output looks like this:
00000000-0000-0000-0000-000000000000

Guid is a struct. Structs can not have a parameterless constructor in C#. That means the parameterless constructor will always just fill the memory with zero bytes. This behaviour is true for all structs and that can not be changed. As you can see here the struct has several constructors that actually take parameters which can be used to initialize a Guid struct. Though those constructores would just fill the struct with the data provided. In the end a Guid is just a container for 16 byte values.

You probably want to generate a new UUID. For this you can use the static NewGuid method. Make sure you read the Remarks section.

_id = Guid.NewGuid();