Use APKPure App
Get Whats|Export|All|Contacts old version APK for Android
Ce qui est | Exporter | Tous | Contacts
This Application Export All Whats Contacts.
This application allow permission for you're using.
Show All the Whats Contact.
Click export button all the contact are save in your external storage.
Automatic create folder in your external storage.
Create the .txt file in this folder.