You guys can download the Postman from here: https://www.postman.com/downloads/
When you download the Postman, you will see the login screen. After you logged in, choose to GET in the interface and paste 'http://127.0.0.1:5000/' into the space next to GET.
We have 4 methods: 'get_chain', 'mine_block', 'is_valid', and 'get_utxos'. I add their description under them.
When you run your program, enter the Postman, and write methods next to the URL. e.g. 'http://127.0.0.1:5000/get_chain'