It’s not possible to change the package name from orchestrator. Package name is set during the publishing process from studio.
So, it has to be changed from studio or by changing the name in project.json file and then republishing the same.
Or you can consider changing the name of the process you are creating from that package. You can choose the new name for the process while underlying package name remains the same.
go to your project in studio..from the projects menu right click and select edit project settings and the change the name as you need and then republish it ..the new name would reflect
you can change in project.json also..buts its recommended to change via UI so that it reflects everywhere needed and removes any naming conflict issues