WebAPP/app/Models/EventCarpoolPassenger.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class EventCarpoolPassenger extends Model
{
    public $timestamps = false;

    protected $fillable = ['carpool_id', 'player_id'];

    protected static function booted(): void
    {
        static::creating(function (self $model) {
            $model->created_at = $model->freshTimestamp();
        });
    }

    public function carpool(): BelongsTo
    {
        return $this->belongsTo(EventCarpool::class, 'carpool_id');
    }

    public function player(): BelongsTo
    {
        return $this->belongsTo(Player::class);
    }

    public function addedByUser(): BelongsTo
    {
        return $this->belongsTo(User::class, 'added_by');
    }
}