1, first open the mobile phone desktop, as shown in the figure below.
2. Then click the Settings icon, as shown in the figure below.
3. After opening the settings, find the first option flight mode in the opened settings window, as shown in the figure below.
Click the open button at the back here. When the flight mode is turned on, it is almost the same as when it is turned off, so that the alarm clock will not ring, as shown below.