Hi @danoti2021! As you are new to the community, when you get a chance, please introduce yourself here.
I’d also encourage you to add a real picture as your avatar because it helps build community!
Are you following the directions here: Setup ODK-X Sync Endpoint with Cloud Services — ODK-X Docs to set up your sync-endpoint on DigitalOcean? What step in are you having trouble with? The unable to authenticate may indicate there was an issue in providing the right token or name for your droplet.