question

public void LogRaceStart(string playersCarName, string category)
{
    var eventData = new Dictionary<string, object>
    {
        {"PlayersCarName", playersCarName},
        {"Category", category}
    };

    SendEvent("Race_Start", eventData);
}


private void SendEvent(string eventName, Dictionary<string, object> eventData)
{   
    if (!PlayFabClientAPI.IsClientLoggedIn()) return;
    
    var request = new WriteClientPlayerEventRequest
    {
        EventName = eventName,
        Body = eventData,
        Timestamp = DateTime.Now
    };

    PlayFabClientAPI.WritePlayerEvent(
        request,
        response =>
        {
            Debug.Log("EVENT SUCCESS");
        },
        error =>
        {
            Debug.Log($"EVENT ERROR {error.Error}, {error.ErrorMessage}, {error.ErrorDetails}");
        });
}

Such implementation of Player Events results in an error massage saying that there are invalid input parameters. Could anyone help with what should be changed or what is missing?