How to tell text is read.
I have an iPhone 12, I turned on iMessaging, and I also can’t find the send read receipts.
iPhone 12, iOS 16
You can turn on send read receipts by going to settings > message > turn on send read receipts. Now this means that people will be able to see if you read their messages but you won't see if they read your messages. For you to see if they read your messages then they will have to turn it on from their device.