You don't import a static library, you link it. i.e. if you have somewhere
#import "ftrapi.a"
this is wrong, it's an object code library, not a header file. Remove all such statements and in the Build Phases tab of your project, add the library to the "Link Binary with libraries" section.
You will also need a header file that you do import into your code. Get the person who built the library to send you the public header(s).