You can now restrict access to your online survey with access codes. This will guarantee that only people with a valid access code can participate in your survey. This is similar to a password protected online survey, only that every participant uses their own personal password.
Simply create a new collector of type “Access Code” and generate random access codes. You can then share those access codes with your participants.
Every access code can only be used once to participate in your survey. An ideal use case is voting, where every person should only be allowed to vote once.