How to trim() white spaces from a string?

I'm having an issue with trimming white spaces from a string in JavaScript. Here's my code:

<script>
  let str = "   Hello,  I need to trim this string.   ";
  let trimmedStr = str.trim();
  console.log(trimmedStr);
</script>

The problem is that the trim() method only removes leading and trailing white spaces, but I want to remove all white spaces. Any suggestions on how to achieve this?