file_get_contents in php not working but browser right click shows source code

I am trying to retrieve some data from https://afsu.edu.tr/ . This is university website. Interesting is when I right click and choose view page source section, browser shows source code.(If you check you will see that source code is not generated by javascript) But when I am using file_get_contents() function in php, it returns empty. I tried cURL , jQuery ajax methods and all not works! please help me to get this website html source code in a variable in php or write them to file(both are good for me).