There can be two situations when GetTouchCount returns a value other than Input.touchCount:
1. You (some script) uses OnlineMapsControlBase.OnGetTouchCount, and returns a different value.
2. On your device Input.touchSupported returns false, and this method returns 1 when the left mouse button is pressed.
Don't be surprised that I write about a mouse on a mobile device, because:
https://docs.unity3d.com/ScriptReferenc … uches.html

You need to understand which case is yours and fix it.
Also, using OnGetTouchCount, you can force Online Maps to use your value (Input.touchCount).

The pinch-zoom function was built-in, as you said.
However, it did not work, so I will let you know the situation.

I checked the touch count in "UpdateGestureZoom()" of the "OnlineMapsControlBase" class, which is probably the pinch zoom process.

Please see the attached image.
There was a difference in the argument "touchCount" and "Input.touchCount".
When pinch zooming with UnityRemote, the "touchCount" value was 1 and the "Input.touchCount" value was 2.

If you have any advice, please let me know.

Pinch to zoom is a built-in Online Maps behavior that is enabled by default and you don't need any script for this to work.

https://forum.infinity-code.com/viewtopic.php?id=1310

However, when I assigned the above script to a map object, it did not work.
I would like to know how to use it correctly.

I ran this environment on Unity Remote.
I am able to move the map by dragging on Unity Remote.