Service accounts provide a way of using OAuth2 without user intervention. They instead assume that the server has access to a private key used to sign requests. The OAuth app is not needed for service accounts: that information is embedded in the account itself.
oauth_service_token(endpoint, secrets, scope =NULL, sub =NULL)
Arguments
endpoint: An OAuth endpoint, created by oauth_endpoint()
secrets: Secrets loaded from JSON file, downloaded from console.
scope: a character vector of scopes to request.
sub: The email address of the user for which the application is requesting delegated access.