@academo I have tried with JSONPlaceholder - Free Fake REST API (typicode.com) and I have the same error.
When I have the log
2024-02-01T10:24:33.074192282Z logger=data-proxy-log t=2024-02-01T10:24:33.073862682Z level=debug msg=Requesting url=https://<company-url-for-elasticsearch>
2024-02-01T10:24:33.277765421Z logger=data-proxy-log userId=1 orgId=1 uname=admin path=/api/datasources/proxy/uid/c64d34d0-f36d-49a7-9822-4674b7cb7820/elastic remote_addr=172.20.0.1 referer="http://localhost:3000/d/f988b064-36b7-440f-ab53-fa9942d20c67/test?orgId=1" t=2024-02-01T10:24:33.277450317Z level=error msg="Proxy request failed" err="Bad Gateway"
2024-02-01T10:24:33.277845895Z logger=context userId=1 orgId=1 uname=admin t=2024-02-01T10:24:33.277580536Z level=error msg="Request Completed" method=POST path=/api/datasources/proxy/uid/c64d34d0-f36d-49a7-9822-4674b7cb7820/elastic status=502 remote_addr=172.20.0.1 time_ms=208 duration=208.565623ms size=0 referer="http://localhost:3000/d/f988b064-36b7-440f-ab53-fa9942d20c67/test?orgId=1" handler=/api/datasources/proxy/uid/:uid/*
And I go to https://<company-url-for-elasticsearch> (first line) I got my data in my browser.
When I put this URL in my fetch method in datasource.ts file, I got CORS issues. When I put the proxy URL I got 502 issue. I don’t know how to unblock the situation.