The type for the div jsx element is HTMLFactory<HTMLDivElement>.

The reference you have isn't for an actual dom element in the browser but for a react element which represent such an element which might not be rendered yet.

The html properties should be accessed through the props:

let element = <div>Blah blah</div>

console.log(element.props.accessKey);

If you'd like to get the dom element you can use the ref attribute:

When the ref attribute is used on an HTML element, the ref callback
receives the underlying DOM element as its argument

So:

let divElement: HTMLDivElement;

let element = <div ref={ (el) => { divElement = el; console.log(el); } }>Blah blah</div>

In the case of the imported Row, again, you have a reference to a react element which has a dom representation.

Which properties or methods it has depends on the class itself.