dariopiana, I installed it today (the modified version from Oxer) and is does work. I did notice that a had to hit "Shift + Q" a few time until i saw "Camera Key 1 added" come up on the status bar. I have up a few time until I noticed that. When you move the camera you have to select "Camera Key maker" again and then hit "Shift + Q" to add key 2 ... so on and so forth. Once you are done hit the "Return" key on the keyboard (not the "Enter" key).
There must be some type of glitch in SketchUp Pro 2018, but it did work.
Hope this helps.