How to set the following three keys of Huawei mobile phone?

The following three keys of Huawei mobile phone refer to "back key", "home key" and "task key", which can be set through the following steps: Open the "Settings" application of the mobile phone. Find the option of "System Navigation" or "Key Navigation" in the "Settings" menu, and click Enter. In the system navigation menu, you can see the setting options of back key, Home key and task key. Click the setting options of "Back key", "Home key" or "Task key" to make corresponding settings, including modifying the function of the key, setting the trigger mode of the key, and modifying the icon of the key.