invoiceninja/app/Models/CompanyUser.php

<?php

namespace App\Models;

class CompanyUser extends BaseModel
{
    protected $guarded = ['id'];

    public function account()
    {
        return $this->hasOne(Account::class);
    }

    public function user()
    {
        return $this->hasOne(User::class)->withPivot('permissions');
    }

    public function company()
    {
    	return $this->hasOne(Company::class)->withPivot('permissions');
    }
}