Read write AD user custom attributes - graph

Question

I want to store some additional user attributes in form of key and value pairs to all the AD users, for example: 'colorTheme:red', 'userLang:english' etc.
I have added these custom attributes using the Azure AD B2C > User Attributes
I am trying to Read and Write as per the below link.
https://learn.microsoft.com/en-us/graph/extensibility-open-users
I did try using the Graph API calls:
GET https://graph.microsoft.com/v1.0/users?$select=displayName&$expand=extensions
I do get the user details but don't get custom attribute
GET https://graph.microsoft.com/v1.0/me/extensions
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('ad-user-id')/extensions",
"value": []
}
How do I get and set the value for the custom attribute?
Is there any other way of storing addition user properties?

Answer 1

The following steps can be used for getting extension properties (custom attributes) defined for a user in Azure AD B2C
Call the following endpoint to get all the existing extension properties. Replace the {{extensionappobjectidwithoutdashes}} with your extension app's object Id without dashes.
https://graph.microsoft.com/v1.0/applications/{{extensionappobjectidwithoutdashes}}/extensionProperties
This will give result that looks something like this. I have removed the guids
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#applications('extensionappobjectidwithoutdashes')/extensionProperties",
"value": [
{
"id": "",
"deletedDateTime": null,
"appDisplayName": "",
"dataType": "String",
"isSyncedFromOnPremises": false,
"name": "extension_<extensionappIdwithoutdashes>_extensionAttribute1",
"targetObjects": [
"User"
]
},
{
"id": "",
"deletedDateTime": null,
"appDisplayName": "",
"dataType": "String",
"isSyncedFromOnPremises": false,
"name": "extension_<extensionappIdwithoutdashes>_extensionAttribute2",
"targetObjects": [
"User"
]
}
]
}
While calling graph api to get user details, add the name of the extension attribute in the select query
https://graph.microsoft.com/v1.0/users?$select=displayName,extension_extension_<extensionappIdwithoutdashes>_extensionAttribute1,extension_extension_<extensionappIdwithoutdashes>_extensionAttribute2
Notes
Use the following docs to see how to create extension properties using ms graph apis
extensionProperty resource type
The extensionappobjectidwithoutdashes and extensionappIdwithoutdashes are different guids. Find them in App Registrations > b2c-extensions-app