set a point to ImagePlane

[hytzgroup]

Hi
I am using xeokit. I have encountered an issue and am here to seek help.
I want to move the center point of the image to the marked point as shown in the image below. Currently, I have modified the code in overlay.js.
I found that in the original overlay.js code, a geometry must be selected; otherwise, it doesn't work.
I have only added an imagePlan and am preparing to scale the image to match the actual size of the basement.
The difficulty I am facing now is how to precisely locate the marked point as shown in the image below? Thank you.