How Do I Use Audio Chat - PS5

So I had my headset on and mic open while playing today, but nobody could hear me. I figured it was a technical issue until suddenly 5 games in someone helpfully told me I should leave the game and never play heavy again.

So, I have no clue how to make my mic work in game. The guy heard me, and I heard him, so it seems like I'm doing something wrong. Voice chat is enabled in settings for "all," and the guy hesring me confirms that. So why can't I use voice?? He said something at the end about "going back to party chat, but I couldn't find any functionality like that.

Can anyone help?