Our app has been online for the past year but in the last one week we have received an insane amount of firebase authentication requests that are not from our users and we are unable to resolve this.
Our app on a daily basis receives about 20 to 30 new registrations but we are receiving tens of thousands of phone authentication requests on firebase. The SMS usage limit is not being reached and at its peak was only about 30 in a day but the requests have spiked. We have not enabled App Check at the time of deploying the App.
We also had to upgrade from the Blaze plan to the Identity Platform as we hit this limit last month.
Any help with this issue would be greatly appreciated as our billing has suddenly increased 10 fold only due to Authentication requests.