add field in rest api

Hi

I was trying to add a field through form-data post man but I got error, you know how to do it or have done something related.

{
“code”: “rest_invalid_param”,
“message”: “Parámetro(s) no válido(s): acf”,
“data”: {
“status”: 400,
“params”: {
“acf”: “acf no es del tipo object.”
}
}
}