Why is there an exclamation mark in some information on the iPhone?

The information icon on the Apple phone has an exclamation mark because iMessage information is not turned on. The solution is as follows:

Tool: iPhone6s

Operating system: iOS 13.4. 1

1. In the interface on the desktop, the information icon has an exclamation mark as shown in the figure.

2. Click the settings icon on the desktop.

3. Open the phone settings interface and click on the information option.

4. Open the information interface and click the switch button in the iMessage information bar.

5. At this time, the iMessage information bar will be light green after it is successfully opened.

6. However, when you exit to the desktop, you can see that the exclamation mark on the text messages on the Apple mobile phone has been removed.