As Noma said, the API is a RESTful API, and it requires a user token per each HTTP call.
To setup a token:
1. First create a Django superuser: `python manage.py createsuperuser`, then follow the prompt. The `email` question is optional, you can leave that blank.
2. Now, you go to the `admin` site. If you run the Netbox by `python manage.py runserver`, then go to `http://localhost:8000/admin`
. You should see the Admin login.
3. Use the username, pwd created in step 1 to login.
4. Scroll towards the bottom of the page, says "USERS", under that section you will see the "Tokens". Click "Add" to add a new token.
5. On the form, select the superuser you created in step 1, and click SAVE, it will generate a token string.
6. Now you can use that string in HTTP calls.
I don't know how Excel issues HTTP call. But these should give you good clue to figure it out in Excel. Hope this helps.