Error .getAttribute is not a function, I don't understand why?

Question

JavaScript

<tab-panel>
   <div data-tabname="one">Tab one</div>
   <div data-tabname="two">Tab two</div>
   <div data-tabname="three">Tab three</div>
</tab-panel>

<script>
function asTabs(node) {
let nArr = Array.from(node.childNodes);
nArr.map(node => {
console.log(node.getAttribute("data-tabname");
//далее другие манипуляции
});
};
asTabs(document.querySelector("tab-panel"));
</script>

I'm slowly learning js. The collection was transferred to an array using Arroy.from
When iterating over in the map method, an error occurs. How to fix?)

Answer 1

childNodes includes text nodes that do not have attributes,
replace with children