1. Turn on the phone and unlock the screen. Note that there is no text above the phone lock screen. 2. After entering the phone function page, find the function icon of "Settings" and click Open. 3. There are two switching columns above. We need to select the function of "Common Settings" column and click to enter Common Settings. 4. After entering the common settings, we scroll down the screen and find the menu item "Unlock Style". 5. Click to enter "Unlock Style", find a menu of "Lock Screen Signature", and click it. 6. A text input dialog box appears on the screen. You can enter the subtitles you want in the dialog box.