ldc-tregalette/app/Traits/Models/ActivityLog.php

<?php

namespace App\Traits\Models;

use App\Observers\ModelObserver;

/**
 * If there is a static function in a trait (named boot[TraitName]),
 * it will be executed as the boot() function would on an Eloquent model.
 * Futhermore, event in the Model observer doesn't erase actual events in the model,
 * but adds them.
 */
trait ActivityLog
{
    /**
     *
     * @return void
     */
    public static function bootActivityLog(): void
    {
        static::whenBooted(function () {
            static::observe(ModelObserver::class);
        });
    }
}