To send a standard text rather than a message through Messages/iMessage on a per-message basis, just do the following on your iPhone:
Tap and hold on the message you want to send as a text. From the pop-up menu, select "Send as Text Message".
Note: Sending a message to a non-Apple device will always be sent as a text, at least unless the other user has an Apple messages compatible app running (unlikely as of 2023).
I usually write a blog post about once a week. The latest post can be viewed here: End of Another Error: I have go to say that this is both a happy and sad milestone in my life. (posted 2025-12-19 at 22:16:32). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2025-11-06 Democracy v Bureaucracy: It's not left versus right which I am complaining about: it is bureaucracy versus democracy!.