Sharepoint API Authenicaton issue.

Question

We are trying to integrate with Microsoft project online. We cannot use cookies, so we are following https://medium.com/@anoopt/accessing-sharepoint-data-using-postman-sharepoint-rest-api-76b70630bcbf to get authentication token.

We've tried to creating application for access token in both:
https://mycompany.sharepoint.com/sites/pwa/_layouts/15/appregnew.aspx
https://mycompany.sharepoint.com/_layouts/15/appregnew.aspx
and use token accordingly. See difference in paw in url.
However, if we use this base URL , we are getting list without any projects. We do have projects under PWA site.
https://mycompany.sharepoint.com/_api/web/Lists

And if we use this URL, we are getting permission issue.
https://mycompany.sharepoint.com/sites/pwa/_api/web/Lists
{
    "odata.error": {
        "code": "-2147024891, System.UnauthorizedAccessException",
        "message": {
            "lang": "en-US",
            "value": "Access denied. You do not have permission to perform this action or access this resource."
        }
    }
}
We were using it in postman. We are not using .net

Answer 1

If yo want this app to access all the tenant,you need to change the Permission Request XML to this:

<AppPermissionRequests AllowAppOnlyPolicy="true">  
  <AppPermissionRequest Scope="http://sharepoint/content/tenant" Right="FullControl"/>  
</AppPermissionRequests>  

The permissions given in the tutorial only allow app access current web site.

More information about add-in permission for your reference:
https://learn.microsoft.com/en-us/sharepoint/dev/sp-add-ins/add-in-permissions-in-sharepoint

Answer 2

I have the same problem and I changed the Permission Request XML, but the issue is still is.

{"error":   
	{"code":"-2147024891, System.UnauthorizedAccessException",
		"message":
			{"lang":"en-US",
			"value":"Access denied."}
	}
}

Answer 3

Hi.

I'm having the same issue as Maryna in that we have 2 customer systems we want to give access to SharePoint from Business Central to upload documents but we get the above error.