getNextUkHorseRacingMarket throwing up error

[RicHep365]

I am just starting to use API-NG after successfully using API-6 for the past 2 years but I am struggling from the off to get anything working.

I have managed to get sessionToken and horseRacingEventTypeId but now I want to list out markets and runners.

I have tried the following from the sample code but get an error:

Call to api-ng failed:
Response: {"detail":{},"faultcode":"Client","faultstring":"D SC-0021"}

$nextHorseRacingMarket = getNextUkHorseRacingMarket($appKey, $sessionToken, $horseRacingEventTypeId);    
    

function getNextUkHorseRacingMarket($appKey, $sessionToken, $horseRacingEventTypeId)
{

    $params = '{"filter":{"eventTypeIds":["' . $horseRacingEventTypeId . '"],
              "marketCountries":["GB"],
              "marketTypeCodes":["WIN"],
              "marketStartTime":{"from":"' . date('c') . '"}},
              "sort":"FIRST_TO_START",
              "maxResults":"1",
              "marketProjection":["RUNNER_DESCRIPTION"]}';
    
    $jsonResponse = sportsApingRequest($appKey, $sessionToken, 'listMarketCatalogue', $params);

    return $jsonResponse;
} 

Help gratefully appreciated

[RicHep365]

Ok, solved it.

Was a missing "/" after listMarketCatalogue...Doh...!!

$jsonResponse = sportsApingRequest($appKey, $sessionToken, 'listMarketCatalogue/', $params);