if this doesn't exist
<div id="flipdown" class="flipdown"></div>
there's an error
Uncaught (in promise) TypeError: Cannot read properties of null (reading 'classList')
at FlipDown._setOptions
Please do a check and return cleanly (stop) if no container node.
if this doesn't exist
there's an error
Please do a check and return cleanly (stop) if no container node.