Update a Specific System Contact

{
  "GsyscContactCode": "KC",
  "GsyscFirstName": null,
  "GsyscMiddleName": null,
  "GsyscLastName": null,
  "GsyscPrefixName": null,
  "GsyscEmpNo": null,
  "GsyscContactDesc": null,
  "GsyscAddCompCode": null,
  "GsyscAddCode": null,
  "GsyscAddLine1": null,
  "GsyscAddLine2": null,
  "GsyscAddLine3": null,
  "GsyscRegionCode": null,
  "GsyscPostalCode": null,
  "GsyscCountry": null,
  "GsyscWorkPhoneNum": null,
  "GsyscHomePhoneNum": null,
  "GsyscMobileNum": null,
  "GsyscPagerNum": null,
  "GsyscFaxNum1": null,
  "GsyscFaxNum2": null,
  "GsyscEmail1": "harry.potter@cmic.ca",
  "GsyscEmail2": null,
  "GsyscWwwSite": null,
  "GsyscClvValueCode1": null,
  "GsyscClvValueCode2": null,
  "GsyscClvValueCode3": null,
  "GsyscClvValueCode4": null,
  "GsyscClvValueCode5": null,
  "GsyscClvValueCode6": null,
  "GsyscPmRoleCode": null,
  "GsyscOther": null,
  "GsyscPrefContactMth": "MAIL",
  "GsyscActiveFlag": "Y",
  "GsyscPartnCode": "013035",
  "GsyscPartnTypeCode": "P",
  "GsyscPrimaryFlag": null,
  "GsyscBidFlag": null,
  "GsyscLastUpdDate": "2022-09-19T17:35:13Z",
  "GsyscLastUpdUser": "DAR",
  "GsyscCollabUserFlag": null,
  "GsyscCollabUsagePrice": null,
  "GsyscHtmlEmailFlag": "N",
  "GsyscIndepContractorFlag": null,
  "GsysAltFaxMethodPrefix": null,
  "GsysAltFaxMethodSuffix": null,
  "GsyscAltFaxMethodFlag": "N",
  "GsyscAltFaxMethodPrefix": null,
  "GsyscAltFaxMethodSuffix": null,
  "GsyscHrssRoleCode": null,
  "GsyscSuffixName": null,
  "GpyempTradeCode": null,
  "GpytrdTradeName": null,
  "GpytrdTradeRate": null,
  "GpytrdTradeChargeRate": null,
  "GpytrdTradeBillingRate": null,
  "GpyempCompCode": null,
  "GpyempWrlCode": null,
  "GpyempWrlName": null,
  "GsyscVUuid": "F2A8505593052DDBE05316821FAC9500",
  "GsyscIuCreateDate": "2023-01-20T02:05:16Z",
  "GsyscIuUpdateDate": null,
  "links": [
    {
      "rel": "self",
      "href": "http://mobtest.cmiccloudr12.com:80/cmictestrti/hcm-rest-api/rest/1/syscontact/F2A8505593052DDBE05316821FAC9500",
      "name": "syscontact",
      "kind": "item"
    },
    {
      "rel": "canonical",
      "href": "http://mobtest.cmiccloudr12.com:80/cmictestrti/hcm-rest-api/rest/1/syscontact/F2A8505593052DDBE05316821FAC9500",
      "name": "syscontact",
      "kind": "item"
    }
  ]
}