To get the collection into the service, it must be included in a view that is published in your service. A simple solution is to add the collection to your start page.
If your startpage is a curated collection then you will find it in the view tab. If you have defined it in another way then you will find it in your collection list.
Go to Content → Collections or Views
Find the “Startpage”
Under the “Metadata”-tab in the bottom, there’s a section called “Collections”
Find your new collection in the dropdown
Select it and click “Add selected collection”
Save the collection