Once again, here's the screenshot I posted for the Samsung Messages app, because I assume you're using the Samsung Messages app to try to record a Voice Message, correct?
View attachment 335674
Look at the lower right. Do you see that icon that's circled? It looks like a bunch of squiggly lines.
That's what you have to long-press (not short-tap, but
long-press) in order to record a Voice Message that then gets sent via the text message app to the recipient, who can then play it on their text messaging app.
Do not use the microphone icon that is part of the keyboard. That is for
dictation only, and will transcribe anything you say into text. I did not include a screenshot of the keyboard in that image
because you don't need the keyboard to record a Voice Message.
Please let me know if this is not clear.