Just by making a request related to the information, then the WhatsApp will provide various information in the form of archive files sent in the form of ZIP with the details of HTML documents and also JSON.
To be able to use this feature, the way is quite easy. Here are the steps:
1. Open the WhatsApp app
2. Select the Settings option - Account - Request Account Info.
3. Press Request Report.
4. The iPhone device screen will display a message that your request has been sent. WhatsApp will then process the request within 3 days of the request.
5. If the request has been received and data related user information has been sent, then you can directly download it easily.
This "Request Account Info" feature seems to be present in order to align the privacy rules of new user data on the European mainland ie GDPR (General Data Protection Regulation).
The regulation states that the user of the application service or social media must provide the feature to download the data easily and completely.