Keycloak OIDC integration

Hi Team,
I am working on the Keycloak OIDC Integration + ATT&CK Workbench Frontend/RestAPI. Unfortunately, I still get "401 Unauthorized" after Keyclock redirects back to the application after authentication.
The testing flow:

1. I open the Workbench webpage and click on the Login button. I also see the "Register" button.
2. It redirects to the Keycloak login page. I enter valid credentials.
3. It redirects back to the workbench webpage with 401 Unauthorized.

Here is my setup / some listings attached:

[root@vps15 attack-workbench-frontend-2.1.0]# cat docker-compose.yml
version: "3.9"
services:
frontend:
container_name: attack-workbench-frontend
image: front-xxx
build: .
depends_on:
- rest-api
ports:
- "82:80"
volumes:
- ./docker-compose-resources/nginx/nginx.conf:/etc/nginx/nginx.conf:ro

rest-api:
container_name: attack-workbench-rest-api
build: ../attack-workbench-rest-api
image: rest-xxx
depends_on:
- mongodb
ports:
- "3000:3000"
volumes:
- ./docker-compose-resources/rest-api/rest-api-service-config.json:/usr/src/app/resources/rest-api-service-config.json:ro
environment:
- DATABASE_URL=mongodb://attack-workbench-database/attack-workspace
- SERVICE_ACCOUNT_APIKEY_ENABLE=true
- JSON_CONFIG_PATH=./resources/rest-api-service-config.json
- WORKBENCH_HOST=http://attack-workbench-rest-api
- WORKBENCH_AUTHN_SERVICE_NAME=collection-manager
- AUTHN_MECHANISM=oidc
- ENABLE_CORS_ANY_ORIGIN=false
- AUTHN_OIDC_CLIENT_ID=workbench
- AUTHN_OIDC_CLIENT_SECRET=Y2lnS0XXXXXXXX6397WzXr9a1
- AUTHN_OIDC_ISSUER_URL=https://vps14.domain.com.pl/realms/edrmetry/.well-known/openid-configuration
- AUTHN_OIDC_REDIRECT_ORIGIN=https://vps15.domain.com
- LOG_LEVEL=debug
- SERVICE_ACCOUNT_OIDC_ENABLE=true
- WB_REST_SERVICE_ACCOUNT_CHALLENGE_APIKEY_ENABLE=true

mongodb:
container_name: attack-workbench-database
image: mongo
volumes:
- db-data:/data/db
ports:
- "27017:27017"

volumes:
db-data:

[root@vps15 attack-workbench-frontend-2.1.0]# cat docker-compose-resources/rest-api/rest-api-service-config.json
{
"serviceAuthn": {
"oidcClientCredentials": {
"enable": true,
"clients": [
{
"clientId": "workbench",
"serviceRole": "collection-manager"
}
]
}
}
}

[root@vps15 attack-workbench-frontend-2.1.0]# docker compose up
....
attack-workbench-rest-api | 2024-08-14T10:05:15.447Z [INFO] ATT&CK Workbench REST API app starting
attack-workbench-rest-api | 2024-08-14T10:05:15.448Z [INFO] Configuring the app
attack-workbench-rest-api | 2024-08-14T10:05:15.448Z [INFO] Starting express
attack-workbench-rest-api | 2024-08-14T10:05:15.872Z [INFO] CORS is not enabled
attack-workbench-rest-api | 2024-08-14T10:05:15.907Z [INFO] Enabling HTTP request logging
attack-workbench-rest-api | 2024-08-14T10:05:15.913Z [INFO] Enabling Swagger UI
attack-workbench-rest-api | 2024-08-14T10:05:16.638Z [INFO] Configuring static routes
attack-workbench-rest-api | 2024-08-14T10:05:17.683Z [INFO] Configured authentication mechanism: oidc
attack-workbench-rest-api | 2024-08-14T10:05:17.685Z [INFO] Configured authentication mechanism: bearer
attack-workbench-rest-api | 2024-08-14T10:05:17.685Z [INFO] Enabled service authentication: client credentials
attack-workbench-rest-api | 2024-08-14T10:05:17.685Z [INFO] Enabled service authentication: challenge apikey
attack-workbench-rest-api | 2024-08-14T10:05:17.685Z [INFO] Configuring REST API routes
attack-workbench-rest-api | 2024-08-14T10:05:18.071Z [INFO] Starting the scheduler
attack-workbench-rest-api | 2024-08-14T10:05:18.071Z [INFO] Starting the HTTP server...
attack-workbench-rest-api | 2024-08-14T10:05:18.079Z [INFO] Listening at http://:::3000
attack-workbench-rest-api | 2024-08-14T10:05:18.079Z [INFO] ATT&CK Workbench REST API start up complete

Keycloak realm has been created with support for OpenID. The Client has been created with Standard Authentication flow. Client authentication is on. Some users like admin@test.com have been added to the Keycloak.

I even modified the scripts/configureKeycloak.js for adding local users to the workbench database => I thought it would lead me to some clue => no luck.

What am I missing? Do you have any idea? Any little hint will be appreciated.
Thanks!

Start by reproducing the 401 flow with the provided docker-compose.yml and rest-api-service-config.json, then inspect scripts/configureKeycloak.js and the REST API authentication setup. Compare the configured OIDC redirect, issuer, client, and user settings with the request and server logs; done means a valid Keycloak login returns an authenticated Workbench session.