Solved bug existed due to difference between mailu domain and hostname difference. also refactored during this to find the bug

roles/web-app-nextcloud/templates/config/oidc.config.php.j2

@@ -11,11 +11,11 @@ return array (
     'lost_password_link' => 'disabled',
 
     // URL of provider. All other URLs are auto-discovered from .well-known
-    'oidc_login_provider_url' => '{{ oidc.client.issuer_url }}',
+    'oidc_login_provider_url' => '{{ OIDC.CLIENT.ISSUER_URL }}',
 
     // Client ID and secret registered with the provider
-    'oidc_login_client_id' => '{{ oidc.client.id }}',
-    'oidc_login_client_secret' => '{{ oidc.client.secret }}',
+    'oidc_login_client_id' => '{{ OIDC.CLIENT.ID }}',
+    'oidc_login_client_secret' => '{{ OIDC.CLIENT.SECRET }}',
 
     // Automatically redirect the login page to the provider
     'oidc_login_auto_redirect' => true,
@@ -36,7 +36,7 @@ return array (
     'oidc_login_default_quota' => '{{applications | get_app_conf(application_id, 'default_quota', True)}}',
 
     // Login button text
-    'oidc_login_button_text' => '{{ oidc.button_text }}',
+    'oidc_login_button_text' => '{{ OIDC.BUTTON_TEXT }}',
 
     // Hide the NextCloud password change form.
     'oidc_login_hide_password_form' => true,
@@ -102,7 +102,7 @@ return array (
         'mail' => 'email',
         'quota' => '{{ ldap.user.attributes.nextcloud_quota }}',
         # 'home' => 'homeDirectory',    # Not implemented yet
-        'ldap_uid' => '{{oidc.attributes.username}}',
+        'ldap_uid' => '{{OIDC.ATTRIBUTES.USERNAME}}',
         # 'groups' => 'ownCloudGroups', # Not implemented yet
         # 'login_filter' => 'realm_access_roles',
     //    'photoURL' => 'picture',

roles/web-app-nextcloud/vars/plugins/sociallogin.yml

@@ -28,13 +28,13 @@ plugin_configuration:
         - name: "{{ domains | get_domain('web-app-keycloak') }}"
           title: "keycloak"
           style: "keycloak"
-          authorizeUrl: "{{ oidc.client.authorize_url }}"
-          tokenUrl: "{{ oidc.client.token_url }}"
+          authorizeUrl: "{{ OIDC.CLIENT.AUTHORIZE_URL }}"
+          tokenUrl: "{{ OIDC.CLIENT.TOKEN_URL }}"
           displayNameClaim: ""
-          userInfoUrl: "{{ oidc.client.user_info_url }}"
-          logoutUrl: "{{ oidc.client.logout_url }}"
-          clientId: "{{ oidc.client.id }}"
-          clientSecret: "{{ oidc.client.secret }}"
+          userInfoUrl: "{{ OIDC.CLIENT.USER_INFO_URL }}"
+          logoutUrl: "{{ OIDC.CLIENT.LOGOUT_URL }}"
+          clientId: "{{ OIDC.CLIENT.ID }}"
+          clientSecret: "{{ OIDC.CLIENT.SECRET }}"
           scope: "openid"
           groupsClaim: ""
           defaultGroup: ""