Use the builtin-worker command to configure the user context that the built-in worker runs under. Available in Octopus 2018.1.0 and later.
Usage: Octopus.Server builtin-worker [<options>] Where [<options>] is any of: --instance=VALUE Name of the instance to use --auto-configure Automatically configure accounts on the local machine with the correct privileges, and set up the built-in worker to use the down-level account. --reset Reset the built-in worker configuration to its factory default, which is to execute scripts using the same account as the Octopus Server itself. --username=VALUE The username for a user account the built-in worker should use when executing custom scripts, like 'octopus-worker' or 'octopus- firstname.lastname@example.org'. Default is to use the same user account as the Octopus Server itself. --password=VALUE The password for the custom account. --domain=VALUE The domain for the custom account. This works best when the user account is defined in a different Active Directory domain where cross- domain trusts are involved. Set this if using a domain account like 'mycompany.com\octopus- worker', otherwise leave it blank to use an account on the local machine, or when using 'email@example.com' (UPN) format. Or one of the common options: --help Show detailed help for this command