Hi Andrew,
Thanks for an answer.
I have formed POST request with json data to _AG map server.
It is pretty simple: when user deletes AG instance from course, it should delete map point on AG map server.
It is ok now (finally). My logic was flawed in beginning. And also it was confusing that Recycle Bin in Moolde took away control of delete_instance function in lib.php. This last thing was hard to debug.
Regards