How to turn on the short message reading function?

Take Apple's mobile phone as an example, you can turn on the read receipt function, and the operation method is as follows:

Tool: iPhone 8

Operating system: iOS 14.4. 1.

1. First, open the settings in the mobile phone, as shown in the figure below.

2. Then drop down in Settings, find the message after the drop-down and click Open, as shown in the figure below.

3. After opening, select Send Read Receipt and click the button behind, as shown in the figure below.

4. When the button behind the sent read receipt turns green, it will be turned on, so that texting others will show that it has been read.