Welcome to our community and thank you for your question.
@Pieter already linked a useful thread here on the community that gives you an overview of the required documents to get married.
As it's stated there, both of you will have to provide a proof of identity (like a passport). I'm afraid that without any document like that you won't be able to marry. It might be that some registry offices (or registry offices in other countries) accept an expired passport or other types of documents instead. But he would have to get there first, which he isn't allowed at the moment as you said.
I know that this sounds disencouraging to you, but even if your fiancé was allowed to travel, I can't see a way for you to get married without the required documents.