zeppelin

Some of those numbers work on that site, however they don't work on big platforms like Twitter, FB etc.. I had the same problem and found out that it's because they are using VOIP based numbers to receive sms and they can be blocked by the big tech companies. Also, as they are public facing numbers, make sure you don't use them for any sensitive accounts! FYI, I ended up using a provider called quackr as they offer non-voip temporary numbers.

I would stay away from any large VPNs like Surfshark, NordVPN etc.. they will sell you out when push comes to shove. You should use a 4G residential proxy on top of a trusted VPN. 4G proxies can vary between $20 - $50 per month so not cheap but they offer good protection when combined with a VPN.