Notebook parameters not passing through RunNotebook API call in Microsoft Fabric

I'm not sure specifically about the API, but do you have a parameter cell in your notebook?

https://learn.microsoft.com/en-us/fabric/data-engineering/author-execute-notebook#designate-a-parameters-cell 

Hi,

I tried this API using Postman successfully. The main differences with yours are the request body that shows below. And also according to the doc https://learn.microsoft.com/en-us/fabric/data-engineering/notebook-public-api#run-a-notebook-on-demand , the status code is 202.

{
    "executionData": {
        "parameters": {
            "p_a": {
                "value": "I sent it 321",
                "type": "string"
            }
        }
    }
}