Syncing multiple OAS files via the CLI

I currently have 3 OAS files for my 3 APIs that I need to add to our API reference in readme. Currently, syncing one file at a time will replace the other files, leaving me with only one API in my docs at a time. I am however able to manually upload multiple OAS files.

How can I sync in multiple OAS files for each of the APIs that I need listed in my public docs?