Firebase Phone Authentication "We Have Blocked All Requests From This Device Due To Unusual Activity. Try Again Later."

I am developing and testing an app. I am getting the following message when I was expecting a text with the 6 digit pen.

{code: "auth/too-many-requests", message: "We have blocked all requests from this device due to unusual activity. Try again later."}

so I tried going to authentication =>Sign-in method =>phone and add a # for testing but i get the following error

error adding test phone number

Does anyone know how to get arround either one of these issues so i can continue testing my app.

Thanks

Per the documentation, you cannot add the phone number of an existing user. You should delete the user that is using your phone number before you can add it to the whitelist.