iTwin Synchronizer Prerequisites
To be able to synchronize data to the iModelHub you will need to install the iTwin Synchronizer desktop application on your machine. You must be added to an iTwin Project, by the Project Administrator or Team Coordinator who has access to "Product Settings Service > Manage Settings" in the CONNECT portal. There should be iModel(s) created in the iModelHub and Synchronizations created by the team coordinator, for your project to which you can push your changes.
To be a Team Coordinator you must have the "Product Settings Service > Manage Settings" enabled in the CONNECT portal for your profile. Your organization's IMS (Identity Management Service) administrator can grant you this permission. You must also have access to iModelHub.
You can read more on RBAC roles here
Once the above prerequisites are set you can start synchronizing your changes as needed.