Where to store .ppk key for sftp

[rutledj]

We have several channels that use a .ppk file for sFTP connections. These are currently stored in a folder in the appliance. We are moving our Mirth's to Azure. Is there a way to save the file (or file contents) within the configuration map and reference those from the channel key file settings dialog? Or do they have to be saved to a folder on the Mirth server?