Hey, thanks for trying to get it working, this is unexpected! The reason we have the localhost in the callback is so that we can write the api key to ~/.omnara/credentials.json, so for future use, you would just use that api key. We temporarily spin up an endpoint on your computer during auth time so that we can send a request to it with the api key.
The workaround is to just login to omnara.com, click on your email at the bottom left, click on "API Keys", and then create an API Key named CLI Key. Then copy that key, and make a file at ~/.omnara/credentials.json, and the contents should be: { "write_key": "<YOUR-API-KEY>" }
Then you can run omnara, and it shouldn't ask you for authentication again. Let me know if this works out!