Hi @noend if the theme at least has a collapsibleblock, or similar, for that section then use that and connect the content either to a dynamic source, or try to use liquid directly {{ product.description}}.
Otherwise it’s an advanced theme customization , to DIY see the Dawn theme for reference implementations of a collapsible behavior.
If you need this customization then contact me for services Contact info in forum signature.
ALWAYS please provide context, examples: store url, theme name, post url(s) , or any further detail in ALL correspondence.