On your gate, if you been allowed Admin access you will have access to the Allowed Tickets list feature.
Go to Settings > Allowed Tickets
On this page you will see a list of the existing allowed ticket lists.
Click the pencil icon under Edit in order to amend a list.
This will open up the list of passes, any selected with a check box under the Allowed column are ones that you will be able to scan within that list's time frame.
Simply check or uncheck any boxes for passes you wish to amend.
Once you are happy, remember to select Submit.
If you have made changes, these will work immediately.