How can i add special keywords (SK) to a PNR in Amadeus?

Question

I'm working on integrating Amadeus into my application, and I need to add special keywords (SK) to Passenger Name Records (PNRs) using PNR_AddMultiElements. Can anyone provide guidance or code examples on how to achieve this using the Amadeus API? Any insights, tips, or resources would be greatly appreciated. Thank you!

See my code below :

<dataElementsIndiv>
      <elementManagementData>
        <segmentName>SK</segmentName>
      </elementManagementData>
      <serviceRequest>
        <ssr>
          <type>PARK</type>
          <status>HK</status>
          <quantity>1</quantity>
          <companyId>LH</companyId>
          <freetext>SYD.CAR WASH</freetext>
        </ssr>
      </serviceRequest>
      <referenceForDataElement>
        <reference>
          <qualifier>PT</qualifier>
          <number>1</number>
        </reference>
      </referenceForDataElement>
    </dataElementsIndiv>