WhatsApp automatically makes backups of your chat history every day at 4 AM and you can uninstall and reinstall WhatsApp to restore messages from this copy. .
Note: You will not be able to access Voice Messages sent and received prior to reinstallation..
If you are unable to restore your chats, unfortunately, whatsApp can not restore your chats, contacts or multimedia files for you..
To back up your chats
1.Open WhatsApp and tap More > settings > chats and calls..
2.Tap backup..
save this in OneDrive?