Sticky warning box

How To
3

I don’t know if this is the solution you need but i did a test according to the website you shared.
You can visit this demo to check it out.

I have created a footer with 2 sections: Content and Fixed Block
image

This is the position Fixed Block
image

Here is the js snippet that I added

<script>
const fixedBlock = document.getElementById("brxe-qnqzdt");//id section Content
const content = document.querySelector("#brxe-bctrps");//id section Fixed Block

function getContentTopPositionRelativeToViewport() {
  const contentRect = content.getBoundingClientRect();
  const topPositionRelativeToViewport = contentRect.top;
	const topPosition = fixedBlock.offsetTop;
	if(topPosition >topPositionRelativeToViewport){
		fixedBlock.style.transform = "translateY(100%)";
	}else{
		fixedBlock.style.transform = "translateY(0%)";
	}
}

getContentTopPositionRelativeToViewport();
window.addEventListener("scroll", getContentTopPositionRelativeToViewport);

</script>```
Hope it can help you