JS div scroll to the bottom

 nextTick(() => {
    
        let right = document.querySelector('.plan-content-box');
        if (right.scrollHeight - right.clientHeight - right.scrollTop > 0) {
    

          console.log('right.scrollHeight', right.scrollHeight);
          let timer = setInterval(() => {
    
            right.scrollTop -= 5
            console.log('right.scrollTop', right.scrollTop);
            if (right.scrollTop = right.scrollHeight - right.clientHeight) {
    
              clearInterval(timer)
            }
          }, 10)
        }
      })