# OAuth2.0 400 Error "Mismatch redirect uri"

**URL:** <https://community.parabola.io/t/oauth2-0-400-error-mismatch-redirect-uri/2475>\
**Category:** Ask a question\
**Tags:** Using-APIs\
**Created:** [August 17, 2022, 6:59pm UTC](https://community.parabola.io/t/oauth2-0-400-error-mismatch-redirect-uri/2475 "2022-08-17T18:59:03Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Wes\_Hadley](https://avatars.discourse-cdn.com/v4/letter/w/d26b3c/32.png) [@Wes\_Hadley](https://community.parabola.io/u/Wes_Hadley)\
**Post date:** [August 17, 2022, 6:59pm UTC](https://community.parabola.io/t/oauth2-0-400-error-mismatch-redirect-uri/2475/1 "2022-08-17T18:59:03Z")

</div>

I am attempting to authenticate the [Bullhorn.com](http://Bullhorn.com) API using OAuth2 and I am getting the following error message:  
“An error occurred during authorization: Access token URL returned a 400 when making a request for the access token. More data here: b’{\n “error” : “invalid\_grant”,\n “error\_description” : “Mismatch redirect uri.”\n}'”

 ![Screen Shot 2022-08-17 at 1.48.52 PM](https://us1.discourse-cdn.com/flex020/uploads/parabola/original/2X/8/85217f8ccb1719ce0fdfb5643a32464db0566a4e.png)

I am setting the redirect URI parameter to **[https://parabola.io/api/steps/generic\_api/callback](https://parabola.io/api/steps/generic_api/callback)** for both the auth and access requests. I’ve attached screenshots of my current settings and parameters. Would appreciate any help with troubleshooting!

 ![Authorization Request](https://us1.discourse-cdn.com/flex020/uploads/parabola/original/2X/4/432bb9aae4c1ab68c404fadb26a8fe77047c8c32.png)  
 ![Access : Refresh Token Request](https://us1.discourse-cdn.com/flex020/uploads/parabola/original/2X/2/24ffea1c7c704c98baf407056199ba5db66800c2.png)

Here are the Bullhorn API Docs: [Bullhorn REST API](https://bullhorn.github.io/Getting-Started-with-REST/)