How to add unsubscribe link?

Write any  line in your email template as following.

Such as:

'Click here for unsubscribing from these email campaigns'

or

'Opt-out from our mailing list from here' etc.

Now select the text.

And open the link option.

1. In the traditional email template option, it will be as follows.

Open link option and paste [UNSUBSCRIBE_URL] in URL and change the protocol as <other> follows.

Kindly Note: Make sure to change the protocol to <Other>

It will be now hyperlinked with Unsubscribe URL.

2. In the Drag and Drop Builder, this option will be as follows.

Kindly Note: Any Custom tag such as [FNAME] or [UNSUBSCRIBE_URL], will only work in actual campaigns, not in test/preview email.