Dear Jira Experts,
The organization I am working for is using Jira Data Center (it has Advanced Roadmap feature) and currently we have created a Roadmap under Plan. However, it currently tracks 1 project.
For example, in the below screenshot, we can import multiple projects under Issue Sources.

In the below screenshot, it is a Roadmap with only 1 project. Now how do I import more projects to the Roadmap called "Test Project 1 Advanced Roadmap" after this roadmap is created? Where is the place that I can import multiple projects to the roadmap?
Thank you in advance!