Calculating height in raster layer pixel wise using QGIS C++ API

I am making a custom QT application using QGIS 3.14 C++ APIs.
I am able to render a raster input file(.Tiff). But sometimes Raster file can be of DTED type(with .tiff extension)(DTED file).

How can I calculate elevation data pixelwise and display it on QgsmapCanvas?

Which API should be called while hovering (or by clicking somewhere on the layer) on QgsmapCanvas.
I need suggestions from the developer’s perspective?

I am not using QGIS standalone application.