Difficulty applying for passport

Hello, Hope someone can help. I am having to apply for a UK passport for my father. He has moved to Africa, but has no address and has asked him to help renew his UK passport. When I apply online, I get stuck when it asks for his address, although he does have access to email. I am wondering what is the easiest way to renew his passport? Is there a way to deliver to my UK address? Then when I travel to Africa I can pass it on to him? Because getting hold of his address is difficult. Thanks in advance.