Which IM is able to export chat like email?

At work, I do main communications (LPO) via email. Rest day to day is done via Whatsapp. It includes text, voice messages, map location & images(deliver notes). One of those orders has an issue and now its escalated to legal issue. Thats when the lawyers wanted me to give full communication.

When I tried to export the complete chat, it only gave the text in ".txt" file and rest of media. Not in a presentable form, like an HTML with all media embedded. Then I has to open it in web mode and take screen shots in A4 size and its a 30 page thick. The whole process was just messy. I could not find a better way.

I realize that whatsappp being proprietary and there are limits. Email is not convenient for quick & short communications.

Telegram & Signal have no option to even export. What are my options?