How do I turn off the microphone in iMessages?

Hello radamo59,

If you mean dictation, this can be disabled with these steps: Dictate text on iPhone

If you are referring to creating audio messages in the Messages app on your iPhone, then there isn't a way to disable that option. The feature is explained further here: Send and receive audio messages on iPhone

In case you wish to provide feedback about this, we'd encourage you to do so here: Product Feedback

Apple reviews all feedback, but you may not hear back on any given. They do not request unsolicited ideas.

Take care.

Hey radamo59,

Thanks for clarifying. At this point, we do recommend the best path forward is to provide feedback about this. Please submit suggestions that you would like to see here: Product Feedback - Apple.

Take care.