Homography Matrix, image projection

I'm doing an exercise to understand how homography matrix works but I'm stuck.

I join the code I've written (mycode,immask) and also the one provided by the exercise and the image I have chosen.

Really thank you if you can help me finishing it and explain the code if you have time too.

[jonas]

Congrats!

[Omar Ali]

please write here how you can solved

[Rena Berman]

(Answers Dev) Restored edit