Hi Evan, you can with the On-Premise deployment.
You can find out more about it here:
Be aware that this is not a ‘prefered’ method from Mendix.
You won't enjoy all the benefits of the Cloud platform (security, maintainance, etc)
If you use the API you can deploy your app without ever going to the developer portal. See the deployment API documentation here: https://docs.mendix.com/apidocs-mxsdk/apidocs/deploy-api/