The specific website "Muzikmp3Indir" is a third-party, unlicensed platform for downloading MP3 files.
It is still widely used in Turkish military training and marches.
The "Gündoğdu Marşı" is a historic Turkish patriotic march dating back to roughly 1922 during the Turkish War of Independence.
You can safely and legally stream or purchase the Söz soundtrack on:
Söz Dizi Müzikleri - Gündoğdu Marşı (uzun) :: video.mail.ru
Created to boost the morale of the Turkish army against Greek forces.