Consent is one of the five lawful processing means defined in the GDPR.
The main purpose of consent is to offer individuals genuine choice and put in control on his/her personal data processing.
Any organisation process personal details of an individuals must pay special attention on consent management and future processing on already collected personal data.

Explicit consent

There is a special category of consent called “Explicit consent” which is required to process special category data and automated decision making. The key difference is, ‘explicit’ consent must be affirmed in a clear oral or written statement.
Like this:

How to add an explicit consent checkbox

When creating a campaign that contains a form that asks for user's data, you can enable the explicit consent checkbox and adapt the links and texts to match your terms.

Just enable the corresponding checkbox at the campaign editor page.

As soon as the agreement text is displayed, you can select the texts and links and adapt them to according to  your preferences like all the other elements on the editor.