My server requires unix socket - how to solve the problem?

I have just finished the course about CodeIgniter, created my first simple application, and I run it on a local server successfully.
However, I cannot install it on my live server as it requires a path to the "unix socket".
I have not encountered any explanation in the official documentation how to create such file and where locate it.
Could you help me in an accessible way how to solve my issue?
Thanks a lot.

Alex