AIO-GDPR-docs-tc-hooks.php

<?php

function explicitPermissionGrantedCallback($user){

    if(!is_null($user)){
        var_dump($user); // WP_User
        echo $user->user_nicename . 'has just just given permission';
    }else{
        // User is not logged in.
    }

}
add_action('AIO_GDPR_explicit_permission_granted', 'explicitPermissionGrantedCallback');