Trigger condition on Brand

Hello, so I am trying to set up a multi-brand zendesk account. I know i can go to the admin centre and create a new trigger selecting something like

Brand is abc

But is it possible to achieve this if I create the trigger via the API? I have tried this:

"conditions": {
            "all": [{
                "field": "Brand",
                "value": "is",
                "operator": "abc"
            }]
        }

but i get this error:

{
    "error": "RecordInvalid",
    "description": "Record validation errors",
    "details": {
        "base": [{
            "description": "Invalid rule target: Brand"
        }]
    }
}

so how can I create a trigger with a condition on Brand using the zendesk API?