I cannot use my jar file on Intellij

Hi,

I created this currency-exchange.jar file and then wanted to use it on another project just to practice as I am a beginner. I cannot understand why it doesn't see my jar file in the project. When I try to import it on my main class it just doesn't recognise my jar file. I don't understand what is wrong with it. You can also see the files from the following GitHub link:
https://github.com/codenarok/currency-exchange


I did not choose the best names for some of my classes I know but it's purely because I am frustrated and I want to get this over with asap :)