How to import and use libsignal-protocol-c in an existing .xcodeProj?

Question

I have already done a chat app and is trying to add encryption to it using Signal Protocol. In their Github page they say to use libsignal-protocol-c. But how can I use it? There is no pod. Should I just add all the files manually to the project? The code is in C not objective C. Can somebody point me in the right direction? https://github.com/signalapp/libsignal-protocol-c