Your iPhone has been updated to run iOS 14. iOS 14 has introduced a new privacy feature which causes an orange dot 🟠 indicator to appear in the iPhone status bar when the device microphone is used by an app.
Additionally, if an app is accessing the device camera, a green dot 🟢 is shown in the status bar.
You can learn more about it in the Apple Support document here:
If you see orange or green indicators in the status bar
With iOS 14, you might see an orange or green indicator in the status bar on your iPhone. These indicators appear when the microphone and/or camera are being used by an app.
An orange indicator 🟠 means the microphone is being used by an app on your iPhone.
A green indicator 🟢 means either the camera or the camera and the microphone are being used by an app on your iPhone.
This is intended to let the user know that an app is using the device microphone and to check against any unintended access to microphone.