How to get username using Eloquent ORM?

Question

PHP

There is the following scheme: Post - User
From the post we get the value of author (user id) and this value must be passed to the Users table, displaying the nickname. How I did it:

Post.php model

public function author() {
        return $this->belongsTo(User::class);
    }

Model User.php

public function post() {
        return $this->hasMany(Post::class);
    }

I'm trying to get a nickname:

I found another solution, but it looks suboptimal for this task, I want to implement it through table links.

$author = User::where('id', $post['author'])->first();

Table with users:

Table with entries:

Answer 1

Solution: it was necessary to specify foreignkey 'author' and ownerkey 'id' :)