The SlackPostMessageAction datatype includes various settings.

Table: SlackPostMessageAction

apiTokenstringyes An API token to authenticate with Slack.
channels[string]yes A list of Slack channels to message.
fieldsSlackFieldEntryyes The fields to include within the Slack message. Can be templated with values from the result (see SlackFieldEntry Table).
useProxybooleanyes Whether the action should use the configured proxy to make web requests.
namestringyes The name of the action.
displayNamestringyes The display name of the action.
idstringyes The unique identifier of the action.
yamlTemplateYAMLyes A template that can be used to recreate the action.
packagePackageInstallationyes The package, if any, of which the action is part (see PackageInstallation Table).

[a] Some arguments may be required, as indicated in this column. For some fields, this column indicates that a result will always be returned for it.