Disable Sell independently your bundles.

To disable your course from selling independently, go to Products > Bundles > Desired Bundle.
Then click the Settings button.
Now, you will arrive at the settings page. Select the "Permissions" option under Pricing & Permissions by scrolling down.
Now you can see the Sell Independently option. By default, each course that you generate will be sold independently. Now disable it.
Once you disable this option, click on the Save button. Now, your product cannot be sold separately from a package.
In the same way, you can disable the Sell independently feature for all of your products, including courses, test series, and mock tests.

By default, each bundle that you generate will be sold independently from other course. If you want to keep them in a bundle, follow the below steps. Once completed, your product cannot be sold separately from a package.