Create a Client and corresponding site by following steps corresponding to your router before following this tutorial.
Select Phone Login in Authentication methods and remember to press Finish
Press the config button to configure the fields asked from guest while logging in.
Validation is supported only on PRO/ENT versions. Do configure an SMS gateway before enabling this feature.
Enable validation to verify phone number upon submission. Spotipo achieve this by sending an OTP to the number via SMS Gateway, and asking guest to enter it before proceeding.
Dont forget to save changes before you press finish button at bottom of the page.