how to use whatsapp on laptop without phone

You can also use your WhatsApp on your laptop without mobile data on,
but if you don't use your phone for more than 14 days,
then WhatsApp will log out of your laptop.

in a nutshell

WhatsApp can also be used on a variety of devices including laptops.

Both the desktop and web versions of WhatsApp offer multi-device support.

We can use WhatsApp on four devices simultaneously.

You can now send messages even without using a smartphone as it is also available online.
WhatsApp recently introduced the multi-device feature, which allows you to use WhatsApp
without using a smartphone.

How to use WhatsApp on laptop or PC without phone