To add an accordion to a product, you can edit Additional Info > Add an Accordion Block.
However if you want to add a same accordion block to all products, instead of doing this manually, you can follow these.
#1. Edit Site Footer

#2. Add an Accordion Block to Site Footer

#3. Use this code to Custom CSS box
footer.sections .accordion-block {
display: none;
}

#4. Use this code to Code Injection > Footer
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('footer.sections .accordion-block').insertAfter('.ProductItem-summary');
});
</script>

#5. Result
