Testing with FirebaseAuth Phone Number verification

Looks like you'll need a new phone and take a break from testing for a bit.
This is straight from Firebase docs:

To prevent abuse, Firebase enforces a limit on the number of SMS messages that can be sent to a single phone number within a period of time. If you exceed this limit, phone number verification requests might be throttled. If you encounter this issue during development, use a different phone number for testing, or try the request again later.

At the bottom of this section

See this section of the Firebase Phone Auth docs. Firebase provides a way to add "whitelisted" numbers for testing purposes. From the docs, these phone numbers do not eat up your usage quota, do not require sending an actual text message and can run consecutive tests on the same phone number without getting throttled.

I tried to use my own phone number until I read this:

Make sure you use fictional numbers that do not already exist. Firebase Authentication does not allow you to whitelist existing phone numbers used by real users. One option is to use 555 prefixed numbers as US test phone numbers, for example: +1 650-555-3434