Im a turkish and marrying a bangladeshi man?

He is living in UK. And I live in Turkey. We will marry in Turkey. He needs a doent that called "Certificate of Capacity to Marry".In Turkish rules he needs to get it from bangladesh emby in turkey. I called bangladesh emby and they said they don't give this kind of doents. He needs to ask his parents. ETC. I could not understand. Please someone tell me which way we should follow? We will marry in Istanbul.