Hi,
You can achieve it by working with the
Run after setting. Start by adding a new step as parallel branch, like highlighted in the image below:

Then search for the Terminate action:
You can set its status to Cancelled, Failed or Succeeded. Based on your description, you must select Succeeded:
So far, both actions from my flow (Success and Terminate) will run concurrently if the Compose action succeeds. As we want to terminate the flow only if we have a failure in the Compose, we must now work with the run after settings.
In the Terminate action, click in the ellipsis(...) (highlighted in blue) and in Configure run after (highlighted in yellow)
Then unselect the is successful checkbox, and select all the others, and click in Done:
After changing this configuration, you must notice that the arrow in your Terminate branch will be dashed and an info button will appear (highlighted in yellow) to let you know that this step will run only under the Run after configuration:
Now let's test the flow. I intentionally put an expression that must fail the action in the Compose. After running it, the Compose action failed, as expected, and the Terminate action was fired (red arrow). As a result, the flow ran successfully (blue arrow) even with a failure in the Compose action:
Let me know if it works for you or if you need any additional help!
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