To enable a landline number, you’ll need a mobile device to host your landline number (this option is available in WhatsApp Business). The step-by-step guide we created uses an Android phone.
WhatsApp Business will request permission to access the device’s files — choose “Continue” to grant access. On the next screen, select your country and enter your landline number.
You’ll receive a code, but since it’s not possible to receive an SMS on a landline, wait until the countdown ends and choose the Call me option.You’ll receive a call from WhatsApp Business that will speak the activation code — just enter it in the indicated field ;)