Records not associated with a user?

I need to get all Services that are not associated with the requests which are associated with a user .

So basically the models are

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */


   protected $fillable = [
        'name', 'email', 'password', 'roles'
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token','profesion_id'
    ];
     public function solicitudes(){
      return $this->hasMany(SolicitudServicio::class);
    }

}

The service request model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class SolicitudServicio extends Model
{
  protected $table ="solicitudes";
  protected $fillable = ['url', 'servicio', 'servicio_id', 'nequipos', 'nequipos_asignados','username','password', 'ndias'];
//Metodo del operador
  public function users()
  {
    return $this->belongsToMany(User::class);
  }

  public function servicio(){
    return $this->belongsTo(Servicio::class);
  }
  public function estado(){
      return $this->belongsTo(Estado::class); //es estado de solicitud
  }

  public function tipo(){
      return $this->belongsTo(Tipo::class); //Es tipo de solicitud
  }
  public function user(){
    return $this->belongsTo(User::class);
  }  
}

The service model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Servicio extends Model
{
  protected $table = 'servicios';
  protected $fillable = ['name', 'description'];

  public function solicitudesDeServicio(){
    return $this->hasMany(SolicitudServicio::class);
  }
  public function funciones(){
    return $this->hasMany(FuncioneServicio::class);
  }
} 

Then as I said, I need the services that are not associated with the services which are associated with a user.

I usually have this query using Relationships which only returns the services that are associated with the services of a user that in this case is the user with id 1.

So what I need is the opposite, I have reviewed the documentation of laravel and there is an interesting function whereNotIn but I have not managed to make it work in the query

$solicitudes = App\Servicio::whereHas('solicitudesDeServicio',function($query) {

    $query->whereHas('user',function($query2) {

        $query2->where('id','1');

    });

})->get();