JavaScript Snippets Aren’t Able To Run Because Of ‘Sandbox=”allow-scripts”‘ Not Implemented [duplicate]

Code Link: here

So, on this given webpage I am doing just repeating data entry task. And I thought to use JavaScript to make things easier.

Panel I wanted to automate

When I wrote the code, it just doesn’t let me do anything. Like I can’t use any event triggers, not even any tedious functions. Even I can’t access the input fields until unless I go into developer tools and specifically select ‘about:srcdoc’ and only then it finds the elements it needs to.

I have never faced this issue. How can i solve this from client side to do what i was doing.

The code i was running is below:

  // Function to handle the onchange event
  function handleChange(event) {
      // Subtract 50,000 from txtListingPriceLow
document.querySelector('input[id="txtListingPriceLow"]').value = (
  (parseFloat(document.querySelector('input[id="txtListingPriceLow"]').value.replace(/[^0-9.-]/g, '')) - 50000)
).toFixed(2);
  }

  // Add event listener to the input element
  var inputElement = document.querySelector('input[id="txtListingPriceLow"]');
  if (inputElement) {
      inputElement.addEventListener('change', handleChange);
  } else {
      console.log('Input element not found');
  }

It throws the error like:

Blocked script execution in ‘about:srcdoc’ because the document’s frame is sandboxed and the ‘allow-scripts’ permission is not set.