Adding a row via API using cURL adds blank row

Hi all:

I'm attempting to add a child row to a sheet using the API and cURL. It took some time but finally, taking information from chatgpt and other sources, I was able to get a row added as a child in the proper place. However, the row is blank and not taking the values I am setting.

curl -X POST https://api.smartsheet.com/2.0/sheets/3571298173144964/rows -H "Authorization: Bearer <TOKEN> " -H "Content-Type: application/json" -d "{\"parentId\":525015721938820,\"rows\": [{ \"cells\": [ {\"columnId\": 4063440565129092, \"Value\": \"Child\"}]}]}"

is setting a child row to the parent as expected, but all cells are blank.

Any ideas what is wrong with the value set?

Thanks

Answers