How do subscriptions work in a target app if there are two different node types in it?

Summary:

We need to achieve a subscriptions between source and target app. But the target app is having two different node types. One separate node type for child and one separate node type for Parent. So, when subscription request is created from source, it is showing error that the target app is having Invalid node type as it is having different Node type.

Any help would be appreciated.

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