//Add new property
ItemResponse<User> response = await _containerResponse.Container.PatchItemAsync<User>(
            id: userIdForDemo,
            partitionKey: new PartitionKey(partitionKey),
            patchOperations: new[] {
                PatchOperation.Add($"/location", "London")
            });

//Update existing property
ItemResponse<User> response = await _containerResponse.Container.PatchItemAsync<User>(
            id: userIdForDemo,
            partitionKey: new PartitionKey(partitionKey),
            patchOperations: new[] {
                PatchOperation.Add($"/name", "Vardhaman Deshpande")
            });