A Lists tool designer can restrict access to forms in the following ways:
Uncheck the option to create items in Settings and Options
If you disable this item, users will not be able to add any new items to the Lists tool.
Select options for excluding a form for workspace members, depending on their role.
This option is described below.
Excluding a form depending on member role
A designer might want to make a form available only to certain members. For example, you might want to allow only managers to add new items, while allowing other members to read these items. You could accomplish this by allowing only the manager role to choose this form in the Lists tool's New menu.
Open the Designer.
Click the form template you want to change.
Uncheck the member roles to be excluded from seeing this form.