Wekan OIDC login with Gitlab

I hope I can change the login in method in Wekan from password to OIDC. I use Gitlab as my Oauth provider, and I already set all the things up as you can see in the picture below. However, I still cannot see the OIDC login buttom when I open the app. If I go to http://localhost:3000/_oauth/oidc the error below will occur: (oauth_server.js:406) Error in OAuth Server: Service not configured

Could someone please give me some hint about this error? I have stuck in here for few weeks...

• My Gitlab settings

• Settings in docker-compose.yml
  • OAUTH2_ENABLED=true
    • OAUTH2_LOGIN_STYLE=redirect
    • OAUTH2_CLIENT_ID=xxx
    • OAUTH2_SECRET=xxx
    • OAUTH2_SERVER_URL=xxx
    • OAUTH2_AUTH_ENDPOINT=/oauth/authorize
    • OAUTH2_USERINFO_ENDPOINT=/oauth/userinfo
    • OAUTH2_TOKEN_ENDPOINT=/oauth/token
    • OAUTH2_ID_TOKEN_WHITELIST_FIELDS=""
    • OAUTH2_REQUEST_PERMISSIONS=openid profile email
    • OAUTH2_ID_MAP=sub
    • OAUTH2_USERNAME_MAP=nickname
    • OAUTH2_FULLNAME_MAP=name
    • OAUTH2_EMAIL_MAP=email

I really appreciate any sharing and help!