# Before you start

Run the scheduler.

1. **Run the scheduler.** The domain checks run from it (see [Scheduler](https://justdocs.qdev.tech/docs/justdocs/configuration/scheduler)).
2. **Let the app answer on any hostname.** Requests for customers' domains arrive with the customer's hostname. Your web server must pass them to JustDocs instead of showing a default page: with Apache, make the JustDocs virtual host the first one; with Nginx, use `server_name _;` or `default_server`.
3. Open **Admin → Settings → Custom domains** and choose one of the three ways to handle certificates below. The **CNAME target** is the host customers point at; empty means your platform's own host.

You can check any domain by hand:

```bash
php artisan docs:check-domains --domain=<id>
```