Non-VoIP
Non-VoIP numbers for SMS
When an app blocks VoIP, it is usually looking for an ordinary mobile number on a carrier network.
Many services inspect the number type before they send a code. VoIP and landline ranges are often refused on sight. A non-VoIP number is a mobile line on a carrier network, which is the type those checks expect.
SmsWays lists numbers by country and network, with the price and a delivery record you can read first. That does not force every app to accept every line, but it skips the ranges those apps usually drop immediately.
If one network is declined, try another country instead of sending the same number again. Once the SMS arrives, the code is on screen in your account.
One-time lines are for a single check. A rental keeps a non-VoIP number for days, which matters when the app will ask for the same phone on the next login.