How to make use of it:

1. Add the back2top.js JavaScript library to the web page.

<script src="back2top.min.js"></script>

2. Create a button on the web page.

<button id="back2top">BACK2TOP</button>

3. Initialize the button and resolve how far the web page is scrolled right down to show this button.

const button = document.querySelector("#back2top");
BACK2TOP(button, 200);

4. Config the graceful scroll conduct.

// BACK2TOP(selector, offset, prop, time, effect, delay);
BACK2TOP(button, 200, "all", 300, "ease", 0);

5. Apply your CSS types to the again-to-top button.

button#back2top{
  position: fixed;
  right: 2%;
  bottom: 2%;
  opacity: 0;
  visibility: hidden;
  font-size: 14px;
  color: #fff;
  background-color: #4F46E5;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 10px 18px;
  margin: 0;
  border-radius: 3px;
}