Hi ayako, and welcome to Dataiku Community 🙂
If I understood correctly what you meant by share a project, you are looking for project permissions. These permissions can be defined by any project administrator, in the Permissions tab of the project's Security page (note that The Security page is in the menu that appears when you hover the three dot in the top navigation bar of your project).
You can there define what user groups can do within your project, such as reading or writing its content for instance. You can read more on the project permissions in the documentation: https://doc.dataiku.com/dss/latest/security/permissions.html
As I said, the permissions are applied to user groups, so you should grant the permissions to the groups to which the users you want belong to.
Hope that helps!
Agathe
