If you have already read the article I think you have already set up your custom domain for email and link tracking. So what next? You should check whether you did it properly:
1. Send a test email with a tracking link. You should follow these recommendations because you should send your test email to your own email address. 3. Open your test email that you send and tap on the link and it should show you where the link leads.
4. If it’s content.docsify.net/….. That means that you custom domain for link and email tracking doesn't work. So you should re-check if you did everything from this guide
If it’s your custom domain, that means that you made everything correctly.