在textarea如何让使用js插入的文本能够被撤销？

// Javascript

let text = document.querySelector('textarea');



text.Onkeydown= ()=>{

  if(event.key === "Tab"){

    event.preventDefault();

    let selectiOnStart= text.selectionStart;

    let selectiOnEnd= text.selectionEnd;  

    if(selectionEnd !== selectionStart){

      let textValue = text.value;

      let strBefore = textValue.slice(0,selectionStart);

      let lineStart = strBefore.lastIndexOf('\n') + 1;

      text.setRangeText('  ',lineStart,lineStart);

      strBetween = textValue.slice(selectionStart,selectionEnd);

      text.setRangeText(strBetween.replace('\n','\n  '));

     

    }

    else{

      text.setRangeText("  ");

      text.selectionStart += 2;

    }

  }

}