OAuth2 Authentication Setup issue with confluence on-prem server

[Deleted user]

When we try to set up OAuth2 authentication in confluence on-prem server using the below steps, we get the 400 Bad request error when requesting the Authorization code.

To create an incoming link.

1. Login into confluence on-prem server  and Go to > General Configuration > Application links.
2. Select Create link.
3. Select External application, and then choose Incoming as the direction.

4. After this we’ll get client id and client secret of application link.

5. Request Authorization code by redirecting the user to the /rest/oauth2/latest/authorize page with the URL.

https://confluence.integ.us-west-2.beta.kendra.aws.a2z.com/plugins/servlet/oauth2/consent?client_id=0cd3c3bcc51f7801d1c0e33e34f8c8cd&redirect_uri=https://confluence.integ.us-west-2.beta.kendra.aws.a2z.com&response_type=code&scope=READ&code_challenge_method=plain&code_challenge=code_verifier

6. After hitting this URL we’re getting 400 Bad Request error on browser.

In addition, we also posted this ticket on the Atlassian Support Team and response was they don’t provide any technical assistance. We can connect with their partners for a chargeable demo.

Referring this documentation to setup OAuth2 Authentication on Confluence on-prem server.

we would appreciate if you could point us in the right direction on how to resolve this issue and set up the OAuth2 authentication on the Confluence on-prem server.

[Ben Bracha]

I found this related article:

https://confluence.atlassian.com/confkb/accessing-the-confluence-consent-page-as-a-part-of-oauth-2-0-configuration-results-in-a-tomcat-http-status-400-bad-request-error-1206791088.html

We have the same issue on jira cloud, but I cannot find a related solution for jira cloud.