Huawei P smart 2019 - How to add more Homescreens

Previously Android version had options to add any number of home screen as desired.

Some versions of Android 9 only come with three home screens, meaning you cannot add multiple home screens manually.

But there is another way to add more than three screens:

For that download a Launcher App. These are third-party user interfaces that allow you to customize your phone in many ways. Most of them allow multiple home screens. A very popular launcher which supports multiple home screens is GoLauncher EX.

Simply go the Play Store and search for GoLauncher EX or another launcher.