Yanirose

Hi All, My mother passed away recently, and my elderly father is currently on his own in the UK. My family are originally from Somalia but came to the UK as refugees and have their UK citizenship My question is as I was going through required documents needed for the applications, I see that birth certificate is required from my father and my own birth certificate. My Father was born in 1945 and as we all know Somalia has been country of war for over 30 years so there are no way we can get his birth certificate or if it was even recorded. What are my options? Thank you in advance