Show up to the government office. Say you don't have a compatible phone. Wait until they find a solution for you.
I guarantee the government is not forcing 95-year-old Betsy in bumfuck nowhere with no cell coverage to learn how to use a phone. They have some solution, they're just not making it obvious.
My government's solution to this, is a physical office, where they will file the paperwork for you. You may have an average wait time of four hours to be seen, and so must devote an entire working day to the effort, but can submit without a phone.