shell-leaderboard/src/app/Filament/Resources/ParticipantResource/Pages/CreateParticipant.php

<?php

namespace App\Filament\Resources\ParticipantResource\Pages;

use App\Filament\Resources\ParticipantResource;
use Filament\Resources\Pages\CreateRecord;

class CreateParticipant extends CreateRecord
{
    protected static string $resource = ParticipantResource::class;

    protected function mutateFormDataBeforeCreate(array $data): array
    {
        $minutes = $data['time_minutes'] ?? null;
        $seconds = $data['time_seconds'] ?? null;
        $milliseconds = $data['time_milliseconds'] ?? null;

        if ($minutes !== null || $seconds !== null || $milliseconds !== null) {
            $data['best_time_ms'] = ((int)$minutes * 60000) + ((int)$seconds * 1000) + (int)$milliseconds;
        } else {
            $data['best_time_ms'] = null;
        }

        unset($data['time_minutes'], $data['time_seconds'], $data['time_milliseconds']);

        return $data;
    }

    protected function getRedirectUrl(): string
    {
        return $this->getResource()::getUrl('index');
    }
}