How do I clear existing bid for Dynamic ad target (i.e. Webpage criterion) using Bing Ads API?

Request:<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
  <AuthenticationToken xmlns="https://bingads.microsoft.com/CampaignManagement/v13">*****</AuthenticationToken>
  <CustomerAccountId xmlns="https://bingads.microsoft.com/CampaignManagement/v13">***</CustomerAccountId>
  <CustomerId xmlns="https://bingads.microsoft.com/CampaignManagement/v13">**</CustomerId>
  <DeveloperToken xmlns="https://bingads.microsoft.com/CampaignManagement/v13">****</DeveloperToken>
</soap:Header>
<soap:Body>
  <ns2:UpdateAdGroupCriterionsRequest xmlns:ns2="https://bingads.microsoft.com/CampaignManagement/v13" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:ns3="http://schemas.datacontract.org/2004/07/System.Collections.Generic" xmlns:ns4="https://adapi.microsoft.com" xmlns:ns5="http://schemas.datacontract.org/2004/07/System" xmlns:ns6="http://schemas.microsoft.com/2003/10/Serialization/">
    <ns2:AdGroupCriterions>
      <ns2:AdGroupCriterion xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns2:BiddableAdGroupCriterion">
        <ns2:AdGroupId>1225956451169681</ns2:AdGroupId>
        <ns2:Criterion xsi:nil="true"/>
        <ns2:Id>2328422030568694</ns2:Id>
        <ns2:Status xsi:nil="true"/>
        <ns2:Type xsi:nil="true"/>
        <ns2:CriterionBid xsi:type="ns2:FixedBid">
          <ns2:Type xsi:nil="true"/>
        </ns2:CriterionBid>
        <ns2:DestinationUrl xsi:nil="true"/>
        <ns2:EditorialStatus xsi:nil="true"/>
        <ns2:FinalAppUrls xsi:nil="true"/>
        <ns2:FinalMobileUrls xsi:nil="true"/>
        <ns2:FinalUrlSuffix xsi:nil="true"/>
        <ns2:FinalUrls xsi:nil="true"/>
        <ns2:TrackingUrlTemplate xsi:nil="true"/>
        <ns2:UrlCustomParameters xsi:nil="true"/>
        <ns2:CriterionCashback xsi:nil="true"/>
      </ns2:AdGroupCriterion>
    </ns2:AdGroupCriterions>
    <ns2:CriterionType>Webpage</ns2:CriterionType>
  </ns2:UpdateAdGroupCriterionsRequest>
</soap:Body>
</soap:Envelope>

Jul 28, 2023 1:21:30 PM com.microsoft.bingads.internal.DefaultMessageHandlerBehaviorImpl handleMessage
INFO: Response:<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Header>
  <h:TrackingId xmlns:h="https://bingads.microsoft.com/CampaignManagement/v13">e2792eab-eba8-4a21-874d-75367b408bcc</h:TrackingId>
</s:Header>
<s:Body>
  <UpdateAdGroupCriterionsResponse xmlns="https://bingads.microsoft.com/CampaignManagement/v13">
    <NestedPartialErrors xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
      <BatchErrorCollection>
        <BatchErrors i:nil="true"/>
        <Code>1515</Code>
        <Details i:nil="true"/>
        <ErrorCode>CampaignServiceBidAmountsLessThanFloorPrice</ErrorCode>
        <FieldPath>AdGroupCriterionBid</FieldPath>
        <ForwardCompatibilityMap xmlns:a="http://schemas.datacontract.org/2004/07/System.Collections.Generic" i:nil="true"/>
        <Index>0</Index>
        <Message>Bid amounts are less than floor price.</Message>
        <Type>BatchErrorCollection</Type>
      </BatchErrorCollection>
    </NestedPartialErrors>
  </UpdateAdGroupCriterionsResponse>
</s:Body>
</s:Envelope>