This is the one.

server/src/middleware/require-logged-in.ts

@@ -1,7 +1,14 @@
 import { NextFunction, Request, Response } from "express";
+import CreateLogCtx from "../logger";
+
+const logger = CreateLogCtx("require-logged-in.ts");
 
 export function RequireLoggedIn(req: Request, res: Response, next: NextFunction) {
     if (!req.session.ktchi?.userID) {
+        logger.info(`Received unauthorised request from ${req.ip} from ${req.originalUrl}`, {
+            auth: req.session,
+        });
+
         return res.status(401).json({
             success: false,
             description: `You are not authorised to perform this action.`,