CORS errors when trying to fetch from new Google Cloud API Gateway

I was testing out the new API Gateway to secure a cloud function for my React application. So far the process has been much nicer than the previous alternatives, but I am currently getting CORS errors when trying to reach out to my API Gateway from my React app. I am setting the CORS headers correctly in my Cloud Function, but I have no known way of doing the same on the API Gateway endpoint. I am using Postman to test a request to the gateway endpoint and everything is working great, so it is just when I request from my React app.

Error: "Access to fetch at 'https://my-gateway-a12bcd345e67f89g0h.uc.gateway.dev/hello?key=example' from origin 'https://example.netlify.app' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled."

Would love some insight into this issue. Thanks!