Automation rule

If you need to automatically set the Catalog Select field value, you can use the Jira Automation feature (the Edit Issue action).

The Catalog custom fields are not available in the default list of fields to set, you should refer to the "Additional fields" section using the custom field name and the required option id. (Awaiting the Jira API improvement to make make the JSON structure easier to create).

How to find option ID

Use the request as following: BASE_URL/rest/api/latest/issue/ISSUE_KEY/editmeta

It will provide you the list of editable fields within the issue. Find a Catalog field and the list of option with their IDs: