As of version 2.29, the way you configure access to enter tracker data has changed. A new concept has been introduced called data sharing. This enables much more granular control regarding how users can interact with data within DHIS2. It has been applied to several objects related to both aggregate and event/tracker data.
A great place to start learning about this new feature is to watch the feature spotlight videos here:
Feel free to post questions and comments related to tracker data sharing under this topic discussion.