I used Key Values - Get - REST API (Azure App Configuration) | Microsoft Learn to observe an existing key vault reference in an app configuration store. You should be able to use PUT https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.AppConfiguration/configurationStores/{configStoreName}/keyValues/{keyValueName}?api-version=2023-03-01
passing a body similar to
{
"properties": {
"value": "{\"uri\":\"https://yourkeyvault.vault.azure.net/secrets/secretname\"}",
"tags": {
"tag1": "tagValue1",
"tag2": "tagValue2"
}
}
}
For the SDK, I found azure-sdk-for-net/sdk/appconfiguration/Azure.Data.AppConfiguration/samples/Sample10_SecretReference.md at main · Azure/azure-sdk-for-net · GitHub which actually leverages SecretReferenceConfigurationSetting
object which accepts the key vault secret name and key vault uri endpoint. You use this object to set the reference in the configuration store
client.SetConfigurationSetting(secretReferenceSetting);