An automation step allows you to perform an action on an issue.
There are five actions available:
Change issue status - This action changes the status of an issue. Alternatively, you can provide the name of the desired status (case-sensitive). This allows to use same definition for different projects in which they have a status with the same name, e.g. 'Done'. If no status with that name is found within the project, this step will be skipped.
Change a user assigned to a field - This action changes the user assigned to a field of type user or user list such as Assignee, Creator, Reporter, Request Participants, or Approvers and custom field.
Add a comment on an issue - Adds a text comment to an issue.
Add/ remove label(s) - Adds or removes a label on an issue
Set entity property - Adds an entity property with a specified key and value.
To check the entity property, use the following API endpoint:
https://jira-instance1.net/rest/api/3/issue/ISSUE_KEYproperties/ADDED_PROPERTY_KEY
For more detailed explanations, refer to the Atlassian documentation.