# Received CORS issue trying to reproduce quickstart demo in Rails

**URL:** <https://community.auth0.com/t/received-cors-issue-trying-to-reproduce-quickstart-demo-in-rails/60143>\
**Category:** Get Help\
**Tags:** rails, cors\
**Created:** [March 26, 2021, 8:28pm UTC](https://community.auth0.com/t/received-cors-issue-trying-to-reproduce-quickstart-demo-in-rails/60143 "2021-03-26T20:28:33Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![luuuis](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/luuuis/32/27105_2.png) [@luuuis](https://community.auth0.com/u/luuuis)\
**Post date:** [April 6, 2021, 10:01am UTC](https://community.auth0.com/t/received-cors-issue-trying-to-reproduce-quickstart-demo-in-rails/60143/4 "2021-04-06T10:01:00Z")

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Thanks @nils,

The important thing here is what is happening in the browser, as that is where CORS errors may pop up.

I can see in your screenshot of the Network tab above that the request to `/authorize` is being initiated by “turbo”. I’m not familiar with that library but from reading [https://turbo.hotwire.dev/handbook/introduction#turbo-drive%3A-navigate-within-a-persistent-process](https://turbo.hotwire.dev/handbook/introduction#turbo-drive%3A-navigate-within-a-persistent-process) it looks like it may be attempting to do a cross-origin fetch of `/authorize`, which is not supported.

The OAuth 2.0 authorization endpoint is not designed to be called programmatically (for example using `xhr` or `fetch` request from Javascript) so you will need to disable Turbo for `/authorize` for this to work.

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_[View the full topic](https://community.auth0.com/t/received-cors-issue-trying-to-reproduce-quickstart-demo-in-rails/60143)._