Oppo mobile desktop calendar is missing. How to set it up?

OPPO mobile phone's own software has been deleted, so you can try to restore it according to the following methods: (here, take the COIOROS/KOOC-0//KOOC-0/.2 version of OPPOFindX3Pro mobile phone as an example)/KOOC-0/. You can recover through the function of "System Uninstallable Application Retrieval" and enter Settings: Application Management to uninstall the system and retrieve the application. Select the application that needs to be restored during installation. The function of "Retrieve System Unloadable Applications" adapts to some system versions, and you can check whether the mobile phone version supports it through this setting path. 2.ColorOS6 and previous versions: Some self-contained applications can be reinstalled in the software store. Enter the software store to search for the corresponding software, and then click Install to use it. 3. You can enter Settings > Application Management > Application List > Display System Program in the upper right corner menu; Search "System Desktop" and click "Storage Occupancy" and "Clear Data" to see if there is this software. The position of the desktop icon originally arranged to clear desktop data will be disrupted. 4. You can go to "Settings" Other Settings "Restore your phone" Erase all data completely "to restore. This operation will erase all data from the phone. Please be careful and back up your data in advance. Due to the different versions of the mobile phone system, the operation path may be slightly different. Please refer to the actual operation interface display of the mobile phone. This answer applies to all OPPO models.