You can copy either one lab or all labs from one course to another. You should have "teacher" role in both courses to perform this operation.
Select "Edit Labs" in the top bar. Then select "Copy Lab" or "Copy Group" -
"Select course" will present a list of all the courses where you have the teacher role -
Select the course and navigate to "Select Lab" which should present you with a list of labs in that course -
Selecting "All Groups" will copy all the lab groups from one class into another. Please note that it might take a few minutes for the copy to be successfully completed.