Not able to see the custom column data in search results

Question

I'm using an API to retrieve search results along with item metadata. But I'm encountering an issue where results from a custom column aren't being returned.

I've created a managed property in the search configuration, but it doesn't seem to be working as intended.

Could you please assist me in resolving this?

Managed Property:

Search Results

API: https://graph.microsoft.com/v1.0/search/query

Request Body:

{
    "requests": [
        {
            "entityTypes": [
                "driveItem"
            ],
            "query": {
                "queryString": "Test"
            },
            "fields": [
                "title",
                "path",
                "ListItemID",
                "taSPCNumber"
				"SPCNumber"
            ]
        }
    ]

}