This is most likely because your phone classified the messages as spam (if you flooded yourself with messages). Either wait a bit or use the much more reliable email feature and enable notifications in your email app.

Make sure you have 2FA enabled on your google account.

Yes. You do not use your email password (we use an app password instead). This app password can be deleted at any time. You are sending a notification from YOUR EMAIL to yourself.

This again is fully dependent on your phone carrier. You can check your sent emails (the email you used for credentials) to see if it sent Note that email notifications are MUCH MORE RELIABLE then texts.

Make sure you're using Blender 4.2 or above.

AT&T, T-Mobile, Verizon, Sprint, Virgin Mobile, Telus, Boost, Cricket, MetroPCS, US Cellular (note that performance is dependent on the carrier's email --> SMS service) (you can enable the email option and choose your own instead https://i.imgur.com/h4zfUsc.png)