There is no server side export of messages, so conversations come out one chat at a time. Open the chat, tap More options then More then Export chat, tap Without media or Include media, then pick a method such as Message, Mail or Add to Notes. Include media attaches only the most recent media sent, and the result is a text file that cannot be read back into WhatsApp. For the account record, tap the menu then Account then Request account info, then click Request account info; the report is ready in about three days and the Ready by date gives the estimate. It downloads as a ZIP holding an HTML file and a JSON file, and it covers account information and settings but not personal messages. The report is deleted from WhatsApp's servers after a limited time, counted down on the Request account info page, and it cannot be requested at all from WhatsApp for Windows or Mac.
What it holds
Customer conversations and the media sent in them, plus the business account information and settings.
Find the size
WhatsApp reports device space, not a record count: Storage and data then Manage storage prints the space WhatsApp takes on the device at the top of the screen and breaks it down per chat. No screen gives a message total, so count the message lines in the exported chat text files.
What to enter on the form
WhatsApp Business in messages, and the year your company started using it. Seller form