Nothing. The page you're using enforces connect-src 'none' in its Content-Security-Policy, which means it is technically incapable of sending your words, or anything else, anywhere. The routing you see happens entirely inside your own browser.
None. There is nothing to opt out of because there is nothing running.
When you tap a phone number or an outside resource (988, the Crisis Text Line, freeCodeCamp, and so on), your device opens that link the normal way. Those services have their own privacy policies. Help Terminal never sees that you tapped.
Help Terminal may add an optional way to reach a person by text or phone. That is a separate, opt-in service — texting or calling it first would be your consent to a reply — and it will have its own clearly posted privacy terms before it goes live. It is not part of this website, and this website will still collect nothing.
Help Terminal is a public service of TMF Advisory LLC, St. Louis, Missouri. Questions: btake71@gmail.com.
Help Terminal routes you toward help; it is not itself an emergency service. If you are in danger, call or text 988, or call 911.