https://onetimesecret.com not working from Turkey (curious)

I am unable to reach https://onetimesecret.com from Turkey, I have to enable a VPN that takes me out of the country. I'm just curious: is it censorship? really? Any idea on how to know the reason? (DNS is the same, while traceroute clearly see tcp is droppet at 81.212.73.69.static.turktelekom.com.tr)