I need help - Importing files from personal PC to Postman

Hello . I need help . I am new to using Postman . My mentor gave me already finished api that I need to set up in Postman . But problem appears when I am trying to import files into postman and it says “Error while importing: format not recognized” . I know I searched already for help but it does not help . I really dont know how to fix this and how to set up working and to actually how you say “test” api with Postman . I searched whole day for the answer but still nothing helps . My mentor wont give me answer too , he says that I must learn on my own :smiley: .

Details (like screenshots):

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How I found the problem:
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I’ve already tried: