cssd-back/app/Services/Media/HasMediaTrait.php

<?php

namespace App\Services\Media;

use Spatie\MediaLibrary\HasMedia\HasMediaTrait as BasicHasMedia;
use Spatie\MediaLibrary\Models\Media;

trait HasMediaTrait
{
    use BasicHasMedia;

    public function main_image()
    {
        return $this->morphOne(Media::class, 'model')->where('collection_name', 'main_image');
    }

    public function main_images()
    {
        return $this->morphMany(Media::class, 'model')->where('collection_name', 'main_images');
    }
}