You receive a credentials related error when deploying to external agents, similar to: "The user name or password is incorrect," "The account name is invalid or does not exist," or "The password is invalid for the account name specified."
Use local accounts when deploying to external agents (e.g. .\LocalAdmin). The agent is unable to retrieve domain credentials while outside of the local area network. You can utilize PDQ Inventory scan-user credentials to set the credentials to be used for each scan and deployment.