How to run a child flow? I have read and checked the requisite steps but still getting an error

[Lexicron]

1. Both my parent and child flows are part of a solution.
2. My child flow has a "respond to a powerapp or flow" action (although I'm not entirely clear what to put in it).
3. I have changed my child flow's run-only users to use a defined connection instead of the default run-only user.
4. My child flow is currently set up to also function as its own standalone flow. It does not use a "when a HTTP request is received" trigger. It uses its own manual triger with user inputs (2 date fields, as you'll see below in the first screenshot).
5. My child flow does not actually need to pass any information back to the parent flow. They just need to run one after another.

My parent flow calls the child flow as its very last step, like so:

My child flow has the response action as its very last step, like so:

And here is my child flow's run user connections:

The error I am still getting:

The workflow with id 'f1959090-aba4-ea11-a812-000d3a6aaf70', name Export Resident cannot be used as a child workflow because it is missing a response action.

What else should I do? Am I supposed to edit my parent flow to somehow receive and validate the response sent by my child flow? How do I do that? Is there an action for that?

I just want two flows to run one after another, so that my users are only required to click one button and not two. Is this absolutely most basic requirement of running a flow from another flow somehow not supported by "run a child flow"? Does it have to be complicated by adding responses and HTTP/JSON whatevers to the recipe?

[Lexicron · Accepted solution]

I solved my problem.

In my child flow, I used the Response action under the Request connection:

And this is my very basic Response action: