The public documentation Create a project in your new Jira experience contains some outdated instructions about how to Create projects using shared configuration.

As described in the documentation, the steps to do so would be:

1. Choose the Jira icon > Projects.
2. Select Create project (top right).
3. Give your project a name.
4. Under Project template, select Change.
5. Choose Create with shared configuration > Select.
6. Under Create project with shared configuration, select the project from which you want your new project to share its configuration.
7. Select Create.

This, however, does not reflect the current behavior. Instead, users should now be expanding the Advanced menu and checking the "Share settings with an existing project" checkbox, as represented in the image below.