How to select a capture area in OBS Studio?

Question

Video broadcast

Added Filter / CropPad, it is not clear how to scale a part of the capture window area with the mouse.
Before that, I captured through the VClip utility in which this is done simply by resizing the window area, but it is
slow. The value is inconveniently driven in manually, with numbers

.
removed, but then nothing at all except the sound is captured