There is no way to get Backup from WhatsApp web because it is a browser version of your whatsapp messenger through which you can see your chat messages on your desktop.
The possible way to get backup is only through your mobile.
Questions & Answers
Questions & Answers
if You are using shared hosting
then contact your hosting provider
or
if you have WHM
then follow these steps
https://www.inmotionhosting.com/support/edu/easyapache/how-to-install-a-php-extension-using-easyapache-4/