How can a mobile phone not display information under the lock screen?

If you use a Huawei mobile phone, take Mate30 as an example, you can follow the following methods:

Go to Settings > Notifications > Lock Screen Notification, and turn on the hidden notification content switch. The screen lock interface only displays the number of new messages, not the content of the messages. Turn off the hidden notification content switch, and the new message will be displayed directly in the lock screen interface.