[keycloak-user] invalid_code error when using openidconnect.net to test auth code flow

[David Erie (US)]

Hello,
I am using https://openidconnect.net to test out the authorization code flow on my Keycloak installation, but I am always getting this error in the log and no token in the response:

type=LOGIN_ERROR, realmId=myrealm, clientId=null, userId=null, ipAddress=..., error=invalid_code

Here's an example of the request:

POST http://myserver:8447/auth/realms/myrealm/protocol/openid-connect/token
grant_type=authorization_code
&client_id=oidc-playground
&client_secret=19709e24-cac8-4ece-8b03-0a40e5c0c765
&redirect_url=https://openidconnect.net/callback
&code=eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..w7Pc9yB_htF5F2_cgqDtZA.Ru7B5B-MgYT6mbGy8ykT2dyFVPRSj11HvgJV6rrFownvVUjKYQ90FaiU17rCxpREWC-znDyhzsz4gV7thmz2okswrIUezzgCtzzRqiXo8EidSFZk51qrs1C7UiYklQjMdqyt0qcDRtuhv6eV8YE-t31l3eeuMmKKrT6ikGy_HazJpoOamGyKbGQBGqaJoi8-dNmTVORC7mVHcvX7IEECA0RaSY-gAoNEFPy4ViaGX0JvHGUjUByFsOrQHUea9Fgm.TZbp9Kkt8IEB_JrOALBCYg

Any help would be appreciated.

Thanks,
Dave