Nextcloud as as OIDC provider

[D1reW0lf]

Describe the bug
Unable to use Nexcloud H2CK/oidc app as a login provider for Rally

To Reproduce
Add the following .env vars:

OIDC_NAME=Nextcloud
OIDC_DISCOVERY_URL=https://nextcloud.url/apps/oidc/openid-configuration
OIDC_ISSUER_URL=https://nextcloud.url
OIDC_CLIENT_ID=[ID]
OIDC_CLIENT_SECRET=[SECRET]
OIDC_NAME_CLAIM_PATH=name
OIDC_EMAIL_CLAIM_PATH=email
OIDC_PICTURE_CLAIM_PATH=picture

According to the app doc https://github.com/H2CK/oidc/wiki/User-Documentation#endpoints , I also tried the following endpoits:

https://nextcloud.url/apps/oidc/openid-configuration
https://nextcloud.url/index.php/apps/oidc/openid-configuration
https://nextcloud.url/.well-known/openid-configuration
https://nextcloud.url/index.php/.well-known/openid-configuration

Additional context
This is what I can find on the logs:

rallly-1     | [auth][error] cZ: "response" is not a conform Authorization Server Metadata response (unexpected HTTP status code)
rallly-1     |     at c$ (/app/apps/web/.next/server/chunks/1736.js:462:4876)
rallly-1     |     at c7 (/app/apps/web/.next/server/chunks/1736.js:462:6926)
rallly-1     |     at eM (/app/apps/web/.next/server/chunks/1736.js:462:44289)
rallly-1     |     at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
rallly-1     |     at async eO (/app/apps/web/.next/server/chunks/1736.js:462:47282)
rallly-1     |     at async eS (/app/apps/web/.next/server/chunks/1736.js:462:49958)
rallly-1     |     at async eU (/app/apps/web/.next/server/chunks/1736.js:462:54155)
rallly-1     |     at async /app/apps/web/.next/server/app/api/auth/[...nextauth]/route.js:1:20491
rallly-1     |     at async rb.do (/app/node_modules/.pnpm/next@15.4.6_@babel+core@7.26.10_@opentelemetry+api@1.9.0_@playwright+test@1.52.0_react-_0314d785ff5c15f857d19489caa2dd52/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:5:21059)
rallly-1     |     at async rb.handle (/app/node_modules/.pnpm/next@15.4.6_@babel+core@7.26.10_@opentelemetry+api@1.9.0_@playwright+test@1.52.0_react-_0314d785ff5c15f857d19489caa2dd52/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:5:25902)