The system makes sure that the survey can be taken only if the invitation is sent to the respondent’s email address via QuestionPro. If any other way of distribution is used the survey will not be accessible.
To set up authentication using email invites only:
Consider, that you have enabled 'authentication using email invites only' in your survey. Now, if you share the survey URL through any other way such as instant messaging apps (Skype, Slack, etc.) and the respondent clicks on the URL then, following message will be displayed:
This feature is available with the following licenses :