startFullscreen can not work in mobile and function scope

Phaser 3
1

I using phaer v3.24.1, and I need to do fullscreen mode.

So I using exapmle code from office.

            if (this.scale.isFullscreen){
            console.log('I want stop');
            this.scale.stopFullscreen();
        }else{
            console.log('I wnat start');
            this.scale.startFullscreen();
        }

It dose’t work, give me Uncaught TypeError: this.scale.startFullscreen is not a function.

But if I using in create() method. It will success.

Why?

And if I using mobile it will not success. (safari/chrome iphone X)

I also read this : https://rexrainbow.github.io/phaser3-rex-notes/docs/site/scalemanager/

Please help me.