Sharepoint REST api - Realm is not a configured realm of the current service namespace error 50169 - azure

Question

I got this error trying to get an auth token from Sharepoint REST api. My SP is cloud based and I am using Postman to test the requests, as a previous attempt similarly ran into a dead end when much troubleshooting back and forth with Msoft lead no where .. Anyway, I have the following error and I was wondering if anyone could help me figure out what it is or how I can troubleshoot this issue.
error_description: "AADSTS50169: The realm 'realm' is not a configured realm of the current service namespace"
error_codes : 50169
I followed this tutorial
Thanks!
Edit: I went through and started again, this tut seems to be working I guess I may have missed a step (my guess is I didn't correctly configure the app permissions with xml when creating the app)

Answer 1

To do authorization of SharePoint online and use REST API via Postman, here is a solution for your reference:
First: get security Token
Access [https://login.microsoftonline.com/extSTS.srf] via Http Post method. The content of the http request is as follows.
<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope"
xmlns:a="http://www.w3.org/2005/08/addressing"
xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-
utility-1.0.xsd">
<s:Header>
<a:Action
s:mustUnderstand="1">http://schemas.xmlsoap.org/ws/2005/02/trust/RST/Issue</a:Action>
<a:ReplyTo>
<a:Address>http://www.w3.org/2005/08/addressing/anonymous</a:Address>
</a:ReplyTo>
<a:To s:mustUnderstand="1">https://login.microsoftonline.com/extSTS.srf</a:To>
<o:Security s:mustUnderstand="1"
xmlns:o="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">
<o:UsernameToken>
<o:Username>[username]</o:Username>
<o:Password>[password]</o:Password>
</o:UsernameToken>
</o:Security>
</s:Header>
<s:Body>
<t:RequestSecurityToken xmlns:t="http://schemas.xmlsoap.org/ws/2005/02/trust">
<wsp:AppliesTo xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy">
<a:EndpointReference>
<a:Address>[endpoint]</a:Address>
</a:EndpointReference>
</wsp:AppliesTo>
<t:KeyType>http://schemas.xmlsoap.org/ws/2005/05/identity/NoProofKey</t:KeyType>
<t:RequestType>http://schemas.xmlsoap.org/ws/2005/02/trust/Issue</t:RequestType>
<t:TokenType>urn:oasis:names:tc:SAML:1.0:assertion</t:TokenType>
</t:RequestSecurityToken>
</s:Body>
</s:Envelope>
The demonstration screenshot in Postman:
And the response content will include a security token as below, we can use this security token to get Access Token of SharePoint.
Second: get Access Token
Here i show you how to get access token of SharePoint online using the security token and SharePoint Rest API.
Access [https://yourdomain.sharepoint.com/_forms/default.aspx?wa=wsignin1.0] via http Post method. The content of the request is the security token that we have got above as below.
And the response as below:
We can see that there are two cookie, rtFa and FedAuth in response header, and these two cookie need to be added to the request in subsequent request.
Third: get Request Digest
Access [https://yourdomain.sharepoint.com/_api/contextinfo] via http Post method with that two cookies which we have got above.
And the response as below:
This is the final Token we want!
Then we can use REST API of SharePoint, we only need to add this token and the previous two cookie, as shown in the following figure.