Another attempt to fix plugin

invenio/plugin/custom_invenio_plugin/__init__.py

@@ -1,15 +1,14 @@
 from flask import Blueprint
 
-blueprint = Blueprint(
-    "custom_menu",
-    __name__,
-)
-
 
 def init_app(app):
     """Initialize application."""
-    app.register_blueprint(blueprint)
-
     from . import views
 
+    app.register_blueprint(views.blueprint)
+
+    @app.before_first_request
+    def init_menus():
+        views.init_menu()
+
     return app

invenio/plugin/custom_invenio_plugin/views.py

@@ -7,7 +7,6 @@ blueprint = Blueprint(
 )
 
 
-@blueprint.before_app_first_request
 def init_menu():
     """Add custom items to main menu."""
     current_menu.submenu("main").register(
@@ -18,6 +17,11 @@ def init_menu():
     )
 
 
+@blueprint.before_app_first_request
+def init_menu_on_request():
+    init_menu()
+
+
 @blueprint.route("/debug-menu")
 def debug_menu():
     """Debug endpoint to view menu structure."""