The LinkControl component allows for adding a link. It is intended for use within the block settings UI that appears in the sidebar.
The link control is just a wrapper for the core URL input component. The only difference is the visual appearance and API is more aligned with other sidebar controls such as the TextControl.
const { InspectorControls } = wp.blocks;
const { LinkControl } = hm.controls;
const { attributes, setAttributes } = props;
<InspectorControls>
<LinkControl
label="Link"
help="Some description text"
value={ attributes.link }
onChange={ link => setAttributes( { link } ) }
/>
</InspectorControls>