Right-click menu NOT Showing on touchscreen display

[Shuuri]

Hi,

I have a Elecrow LCD Display with TouchScreen. I managed to get it connected to my Raspberry Pi 2. The Raspbian desktop is shown on the screen. However, when I trying on the right-click menu (long-press on the screen), nothing is shown.
So far, I had tried on
1. Perform calibration using Xinput-calibrator. --> still the same.
2. Changed to evdev from libinput (pi default input library). ---> still the same.

Do anyone know what should I do to get the right-click menu on the touchscreen?

Thanks.