Correct JSON for custom drop down (single select) field?

Question

I am using automation to copy values between tickets and have noticed that drop down and lookup fields are not passing.  What is the correct method to pull these fields?

Error: Could not find valid 'id' or 'value' in the Parent Option object. (customfield_10254)

Example from JSON

"customfield_10254":"{{triggerIssue.fields.customfield_10254}}"

cristiano_madeira · Answer

{
    "fields": {
        "customfield_10254": {
            "value": "{{triggerIssue.fields.customfield_10254}}"
        }
    }
}

wwalser · Answer

Custom fields should show up in the field dropdowns when the project that an automation will run in is known and the custom fields are available within said project.

The advanced field editing field is, as its name suggest, an advanced topic but documentation is here: https://support.atlassian.com/jira-software-cloud/docs/advanced-field-editing-json/