This illustration shows the middle of the Cloud Manager Instance section of the Create stack, Configure variables page.

On the left there are icons indicating the workflow:
1 Stack information
2 Configure variables, which is selected.
3 Review

Under SSH Public Key there are two options:
-Choose SSH Key File (selected)
-Paste SSH Key
There is a field with Drop a file. There is a Browse link. There is a sample file.

There are the following fields with sample text:
-API Private Key
-API Private Key Passphrase Optional
-Tenancy Home Region