This assumes you have created a static inventory in Tower.

1. In the left panel of Ansible Tower, select Inventories.
2. Select the inventory you want to appened managed hosts to.
3. Select the Hosts button.
4. Select the green plus icon.
5. In the New Inventory form, enter the following:
   1. Host Name = the host name of the managed host, such as server1.example.com
   2. Description = Optional
6. Select Save.

In this example, foo inventory contains a single managed host, server1.example.com.