Include Dolphinx in C++14 CMAKE application

I’m having a great deal of trouble getting a working installation for FEniCS or Dolphinx. What I am trying to do is include the Dolphin header files in a cmake c++ application. Specifically, I would like to apply some of the ufl functions like grad_nabla to a triangular mesh generated using VCGLIB. I will be using this code on a cluster where Docker will not be available. So, when someone wants to use Dolphin header files in their c++ application, what do they do to get this code working? Also, my application uses C++14 and I believe that Dolphinx requires c++17. I suppose I will need to use an older version of the code?

I hope this isn’t all too vague.