TypeError: Failed to fetch when calling fetch from the Javascript action

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  • I am running a javascript action that attempts to do a GET request using fetch. I am using the exact example that shows up in documentation for that rule.

    async function getPost(id) {
      return await fetch(`https://jsonplaceholder.typicode.com/posts/` + id)
        .then((res) => res.json());
    }
    
    [[POST]] = await getPost(1);
    

    However, when I call this code it always fails with the message "TypeError: Failed to fetch". Does anyone know what I'm doing wrong?