You can go file TokenCodeResource.java line 48 in folder keycloak-phone-provider/src/java/cc.coopersoft.keycloak.phone/providers/rest and see what it does

code

` // everybody phones authenticator send AUTH code
if( !TokenCodeType.REGISTRATION.equals(tokenCodeType) &&
!TokenCodeType.AUTH.equals(tokenCodeType) &&
!TokenCodeType.VERIFY.equals(tokenCodeType) && // <----- remove this will be stop unregistered , but everybody phones authenticator will be fail.
Utils.findUserByPhone(session, session.getContext().getRealm(), phoneNumber).isEmpty()) {
throw new ForbiddenException("Phone number not found");
}

`