Can't create a schema extension - azure-active-directory

Question

I am trying to create a schema extension in Microsoft Graph API.
But it has failed with error message "Property type is invalid for target types".
POST https://graph.microsoft.com/v1.0/schemaExtensions
Content-type: application/json
{
"id":"extendedData",
"description": "Graph Learn training courses extensions",
"targetTypes": [
"Event"
],
"properties": [
{
"name": "courseId",
"type": "Integer"
},
{
"name": "materialId",
"type": "Integer"
},
{
"name": "courseType",
"type": "String"
}
]
}
Response
{
"error": {
"code": "BadRequest",
"message": "Property type is invalid for target types.",
"innerError": {
"date": ...,
"request-id": ...,
"client-request-id": ...
}
}
}
Why can't I create a schema extension and what error means?

Answer 1

Integer type in properties is not supported for Event targetTypes based on Supported property data types.
You could change them to String.
Please note that you may will encounter a new error: Attempt to update complex extension definition on application: dexxxxx5-d9f9-48b1-a8ad-b7xxxxx25064 belonging to different context.
If you get this error, it means you still need to put an owner property in the JSON payload. (If you don't get this error, it's unnecessary to put owner property)
Register an Azure AD app and put the application id as the owner.
POST https://graph.microsoft.com/v1.0/schemaExtensions
Content-type: application/json
{
"id":"extendedData",
"description": "Graph Learn training courses extensions",
"targetTypes": [
"Event"
],
"owner": "{application id of an Azure AD app}",
"properties": [
{
"name": "courseId",
"type": "String"
},
{
"name": "materialId",
"type": "String"
},
{
"name": "courseType",
"type": "String"
}
]
}