After having set up your Package.
You wish to bill it as such.
So that the guests only see the package they booked instead of a list of the various products that were attached to their rate.
You will have to add the option Bill as package in 2 places:
Stay settings > Options
In the Options of each of the products that should be Billed as package
The option Has expanded bill items should not be ticked in the Stay options.
The Stay options should look like this: