Translation Memory - updating units by source text and translation text

Hello

I want to update unit in my translation memory, here is my example request

{  
  "translationUnit":{  
    "source":{  
      "language":"am-et",
      "text":"sourceTextValue"
    },
    "target":{  
      "language":"gsw-fr",
      "text":"translationTextValueNew"
    }
  },
  "settings":{  
    "existingTUsUpdateMode":"OverwriteCurrent",
    "fieldValues":[  
      {  
        "fieldName":"fieldName1",
        "values":[  
          "fieldNameValue1"
        ]
      },
      {  
        "fieldName":"fieldName2",
        "values":[  
          "fieldNameValue2"
        ]
      }, 
    ],
  }
}

I would like to unit that matches source, target, sourceText to be updated by new value from text-target( value from

    "target":{  
      "language":"gsw-fr",
      "text":"translationTextValueNew"
    })

 

Thx for help