WooCommerce
Create a new woo product from the WooCommerce product creation screen.
By default, the course product type’s quantity cannot be increased. So, to allow users to purchase multiple copies of a single course, set the product type as Simple Product and check Enable Group Registration option
Select the ‘Related Courses’ for the product.
If you check the Allow users to check “Enable Group Registration” on the Front End, setting then the user will have to check this option before making a purchase. If this is not checked, all purchases will be group purchases
Easy Digital Downloads (EDD)
To allow users to purchase multiple copies of a single course, create a Download and check the Is this a LearnDash Course option
Then, select the course and check the Enable Group Registration for the product, and publish the Download.
Disable the Guest Checkout. Go to the Dashboard ➞ Downloads ➞ Settings ➞ Misc ➞ Checkout Settings and check the Require Login checkbox.
Go to the Dashboard ➞ Downloads ➞ Settings ➞ Misc ➞ Miscellaneous and check the Item Quantities checkbox. This will allow users to increase the quantity of the product for a group purchase.