The team is a private project site. Both project sites are within the same organization.
Good morning and welcome!
Do you mean you’d like to convert a private project into a shared team project?
Project administrators can convert any project to a Private Project from the project settings window. To do this, simply:
You can read more here.
If you'd like to duplicate your project and then convert it, so that you have one as a private version and one as a shared version, please follow the steps here.
Let me know if you have any more questions!