Error 401 Unauthorized in POSTMAN - Testing NAV 2018 API

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Posted on by stevenleo

Dear experts,

I'm testing the API NAV 2018 cu 2 to integrate with demo e-commerce website. my problem is i cannot connect to the api from using ip or computer name. with chrome everything is fine, however when i tried using POSTMAN it shows error 401.

6170.22222.png

>>>> this image shows available api when i access via chrome

6170.22222.png

>>>> this is the error when i tried using POSTMAN. i tried to change the authentication type to basic, but not working.

I also have followed the steps in another blogpost by saurav. but the image shown in that post all shows using localhost instead of ip or computer name.

anyone can help???

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Stefano Demiliani 37,166 Most Valuable Professional on at

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Is the request Header the same in all two cases (Chrome and Postman)?

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Suresh Kulla 50,243 Super User 2025 Season 2 on at

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Check the Headers and specify the Authorization properly. check this link

www.getpostman.com/.../authorization

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stevenleo 10 on at

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@stefano, yes it is identical.

@suresh, already tried using basicauth, with my administrator user & password. but it is not working.

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Suresh Kulla 50,243 Super User 2025 Season 2 on at

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For the password use the Web Service Access Key.

docs.microsoft.com/.../devenv-develop-connect-apps-for-fin

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stevenleo 10 on at

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still not working

i wonder if i doing something wrong?

i tried to deploy another VM in azure, but i'm still facing the same problem.

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Andrey Baludin 3,941 on at

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I've run it with Postman only after changing authorization to NTLM on NAV Instance and at Postman. So try this way.

My experience is here:

community.dynamics.com/.../how-to-obtain-data-from-nav-standard-apis

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Saurav.Dhyani 14,380 Super User 2025 Season 2 on at

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Hope this helps!

saurav-nav.blogspot.in/.../microsoft-dynamics-nav-2018-api-part-3.html

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Community Member on at

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Had the same issue, Error 401 when using Postman, but everything worked fine from Chrome.

I used NTLM authentication to resolve it.

Set Service Tier to "Use NTLM Authentication" (General Section)

Use Postman (windows application not Chrome extension) and in the Authorization tab select "NTLM Authentication". Enter correct credentials of user in the DB.

Hope this helps

Dave

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Community Member on at

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Hi,

Do you have NST authentication as "Windows"? Try to set it as "NavUserPassword"

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sanpatHemlock 5 on at

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NTLM authentication works perfect! Thnx.

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