Models do not require an inventory tag initially. After importing your models, you can create a consumable asset. You can do this either manually or by importing it. When you create the consumable asset, you must provide an inventory tag.
Follow the steps below:
Create a Resource Group.
Create an Asset type.
Create a Manufacturer. It can be imported or created manually.
Create a Model Category (Parent/Child). It can be imported or created manually.
Create a Model. It can be imported or created manually.
Create an Asset (this one will require an Asset/Inventory Tag). It can be imported or created manually.