How to set Unsubscribe URL using HTML editor?

To set Unsubscribe URL using HTML Editor, use this Unsubscribe URL merge tag:

{{unsubscribe_url}}

The HTML code should be this:

<a href="{{unsubscribe_url}}">Click to Unsubscribe</a>

Here is an example on how to set Unsubscribe URL using HTML Editor:

Setting the unsubscribe url merge tag in Compose email of HTML Editor