Zoom in/out function by multi touch

[SeulYS]

Hi. i'm Seul.

We're using pdf viewer on a touch monitor. The OS is Windows10.

We want to zoom in and out by using multi-touch functions instead of using button at the top.

We already use preference settings. Touch mode is ‘Auto-Detect’.

Click, Drag, Scroll and Write down, they are all being used as a touch.

However, I can’t zoom in/out by hand touch motion. Like that picture.

Is this impossible at the window?

thank you

Seul.