To get a free* phone number that can be used for regular phone calls/texting, download TextNow or its alternative apps. This number can also be used for WhatsApp, Viber, Facetime or any other platforms registration/verification.
*TextNow also provides permanent phone numbers or you can port your own number using TextNow subscription.
**Use your free TextNow phone number at least a couple of times per week not to lose it. You can also purchase Ad Free+ subscription to keep your TextNow phone number.