Hi Mec Mec , we have databricks migration too that will help you to migrate all the notebooks.

https://github.com/databrickslabs/migrate

If your requirement is to copy only a single notebook you can export it from the old workspace and import it to the new one.

To export a folder you can do the below:

Please refer to the below link for more information.

https://docs.databricks.com/notebooks/notebooks-manage.html#notebook-external-formats