<?php

namespace App;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Laravel\Passport\HasApiTokens;

class User extends Authenticatable
{
    use HasApiTokens, Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    public function votes()
    {
        return $this->hasMany(Vote::class);
    }
}

<?php

namespace App;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Laravel\Passport\HasApiTokens;

class User extends Authenticatable
{
    use HasApiTokens, Notifiable;

    public function votes()
    {
        return $this->hasMany(Vote::class);
    }
}

--- 
+++ 
@@ -10,6 +10,24 @@
 {
     use HasApiTokens, Notifiable;
 
+    /**
+     * The attributes that are mass assignable.
+     *
+     * @var array
+     */
+    protected $fillable = [
+        'name', 'email', 'password',
+    ];
+
+    /**
+     * The attributes that should be hidden for arrays.
+     *
+     * @var array
+     */
+    protected $hidden = [
+        'password', 'remember_token',
+    ];
+
     public function votes()
     {
         return $this->hasMany(Vote::class);
Add fillable fields to user
