exchange-2.0/app/Models/UserAffiliate.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Relations\BelongsTo;

class UserAffiliate extends AbstractModel
{
    protected $table = 'user_affiliates';

    protected $fillable = [
        'user_id',
        'affiliate_id',
        'clicked_at',
        'registered_at'
    ];

    protected $dates = [
        'clicked_at',
        'registered_at'
    ];

    /**
     * @return BelongsTo
     */
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    /**
     * @return BelongsTo
     */
    public function affiliate(): BelongsTo
    {
        return $this->belongsTo(Affiliate::class);
    }
}