export multiple WhatsApp conversations to .txt or .csv format
The manual way of doing that is

&gt; To email your chat history, follow these steps:
&gt; 1. Open the chat you want to send by email.
&gt; 2. Touch More options.
&gt; 3. Touch More.
&gt; 4. Tap Export chat.
&gt; 5. Choose NO FILES or INCLUDE FILES.
&gt; 6. Select the onedrive application and load. The email will be sent as a text. When the history is sent with attachments, only the most
&gt; recent 10,000 messages are sent. Without files, you can send up to
&gt; 40,000 most recent messages. These restrictions are due to the maximum
&gt; size of the email.