If you are using construct 3 on mobile then it will be something like that.
Mobile is a small screen,It's better to use an iPad if you have one.
When the manual says left-click,tap
When the manual says right-click,tap and hold
When the manual says double-click,double-tap
On mobile,Construct 3 will hide the bars you can access them by swiping the sides
You can also change mode by going to Menu-Settings and changing the UI Mode to Desktop.
It's better to use an iPad as a small laptop.