You will need to add a placeholder link or text to your email. The format of that placeholder depends on your Email Service Provider. For example, in MailChimp this is how these placeholders are called Merge Tags. You can read more about it here.
MailChimp is using the tag *|UNSUB|* for unsubscribe links.
What you need to do in Chamaileon is, to add an unsubscribe text in the footer. Mark the text and add a link with the hyperlink icon as you can see in the screenshot below.
Set it as URL, for Protocol <Other> and type in *|UNSUB|* in the URL box. Check the screenshot below.
If you are using Intercom for example, here is how the tag will look like.
Always firstly check with your ESP what is the correct tag and add it in Chamaileon. Then export the HTML code with the correct tag to your ESP.