Update server.js

server.js

@@ -13,10 +13,13 @@ function generateRandomHex(length) {
     return crypto.randomBytes(length).toString("hex");
 }
 
+const rand = (length) => 
+  [...Array(length)].map(() => (Math.random().toString(36)[2] || '0')).join('');
+
 app.use("/tmp", express.static(tempDir));
 
 app.all("/", async (req, res) => {
-    const captcha = new CaptchaGenerator({ height: 200, width: 600 })
+    const captcha = new CaptchaGenerator({ text: rand(6), height: 200, width: 600 })
 
     const fileName = `temp_${generateRandomHex(8)}.png`;
     const filePath = path.join(tempDir, fileName);