I’m enhancing my existing business-tool web app by adding phone-based OTP verification through Firebase. The job is limited to the web platform—no mobile work is required—and the one-time codes should trigger during both new-user registration and every subsequent login. What I need from you: configure my Firebase project for phone authentication, wire the client-side flow into the current authentication pages, handle any necessary back-end token checks, and test end-to-end to be sure users receive and confirm their SMS codes smoothly. Clear, commented code plus a brief setup note so I can reproduce the steps in staging will complete the work. If you’ve done Firebase phone auth before and can get this running quickly, let’s talk.