You can use the following three property tags to update the VGM fields through the ICU API:
VGMWeightKgValue
VGMEntityVerifier
VgmVerifiedDate
The following code snippet shows an example using the ICU API to update the VGM fields:
<icu>
<units>
<unit-identity id="JEYU144583" type="CONTAINERIZED">
<carrier direction="IB" qualifier="DECLARED" mode="VESSEL" id="JEY1001"/>
</unit-identity>
</units>
<properties>
<property tag="VGMWeightKgValue" value="25463"/>
<property tag="VGMEntityVerifier" value="VGM verifier name"/>
<property tag="VgmVerifiedDate" value="2016-11-26"/>
</properties>
</icu>