To create a WhatsApp subscriber profile, there is no need to come up with a login; you just need to link your account to a phone number. The login password is sent to your phone via SMS. Some users express a desire to use the application without a SIM card. Although the authors of the application did not provide such an option, the user can use a workaround to enter the service.

https://messeng.ru/nuzhna-li-sim-karta-dlja-vatsap/

The role of a phone number when communicating via WhatsApp
The WhatsApp subscriber profile is assigned to a specific phone number, which is used for initial authorization. Subsequent communication does not require constant use of the phone, so in the future the user will be able to use WhatsApp functionality without a SIM card.

The application can be used even on devices that do not have SIM card slots.

Installing messenger without a SIM card

To activate WhatsApp without a phone number, use third-party software, a landline phone, or a card installed on another device.