How to import a Private Key to an Azure App? Issues with App Permissions and Certificates for Runbook

Question

I am running into this issue where I am not able to upload a private key file to an Enterprise Azure app. I do not see the option to do so - see below image. It only lets me use a public key, which I am not able to use for Runbook.

Due to this, I am unable to get the necessary admin permissions to run my scripts in Azure from my Runbook, because it is asking for a private key.

Essentially, when I run my Runbook from my Automation account, I would like for the Runbook to look at the Enterprise app for admin permissions, instead of a user account.

If there is a better way to accomplish this for my Automation account, where it looks at app permissions instead of a user's permissions, that would be ideal.

Thank you