How do I stop anonymous texting response on iPhone?

Blocking Messages:

A. Report this Message:

So, report phone call's and messages info to Apple and others (such as your government). Use my User Tip: Using the Photos App to Report Scams - User Tip

B. App Called "Bouncer":"

Bouncer is an app that blocks out text messages from certain senders — all filtering is based off of keywords and phrases. You can customize it. It is forums right in the App Store. Get it Here: Bouncer: Text Messages Blocker 4+ - App Store

C. Malwarebytes Mobile Security:

If you were to use Malwarebytes Mobile Security then that may do the job, somewhat. It blocks out suspected scams, based on the sender's phone number. The paid version lets you report a number - once reported, it blocks it out, not even allowing it to go through.  Malwarebytes is created by longtime users of these forums, making it the only reliable Security Software for Apple devices. Go Here: Malwarebytes Mobile Security - App Store

Hello!

Please go to: Settings > Focus > Driving > Auto-Reply. What does the “Auto Reply Message” say?