You'll need to be more explicit about what you think "Phone OTP" is and what you think "refuse" means.

Phone as in, "the OTP requires a cell phone with yet another buggy authenticatoin app"? Or phone as in "can support SMS"? Or phone as in "phone must support touch-tone"? Phone as in "the user must be able to hear and speak?"

"Refuse" as in, "I'm in the unpopulated area of Washington state and I have no phone signal"? Or refuse as in "I'm not using my personal device for work"? Or rfuse as in "I don't use smart phones because I want to live in the moment"?