diff --git a/package-lock.json b/package-lock.json
index f78aa40..2c2e096 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,7 @@
       "dependencies": {
         "did-jwt": "^6.0.0",
         "jose": "^4.6.0",
+        "readline-sync": "^1.4.10",
         "web-did-resolver": "^2.0.14"
       }
     },
@@ -299,6 +300,14 @@
         }
       }
     },
+    "node_modules/readline-sync": {
+      "version": "1.4.10",
+      "resolved": "https://registry.npmjs.org/readline-sync/-/readline-sync-1.4.10.tgz",
+      "integrity": "sha512-gNva8/6UAe8QYepIQH/jQ2qn91Qj0B9sYjMBBs3QOB8F2CXcKgLxQaJRP76sWVRQt+QU+8fAkCbCvjjMFu7Ycw==",
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
     "node_modules/tr46": {
       "version": "0.0.3",
       "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
@@ -608,6 +617,11 @@
         "whatwg-url": "^5.0.0"
       }
     },
+    "readline-sync": {
+      "version": "1.4.10",
+      "resolved": "https://registry.npmjs.org/readline-sync/-/readline-sync-1.4.10.tgz",
+      "integrity": "sha512-gNva8/6UAe8QYepIQH/jQ2qn91Qj0B9sYjMBBs3QOB8F2CXcKgLxQaJRP76sWVRQt+QU+8fAkCbCvjjMFu7Ycw=="
+    },
     "tr46": {
       "version": "0.0.3",
       "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
diff --git a/package.json b/package.json
index c5ae345..78e03ec 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
   "dependencies": {
     "did-jwt": "^6.0.0",
     "jose": "^4.6.0",
+    "readline-sync": "^1.4.10",
     "web-did-resolver": "^2.0.14"
   }
-}
\ No newline at end of file
+}
diff --git a/src/config.json b/src/config.json
index f2921db..8e1e5a5 100644
--- a/src/config.json
+++ b/src/config.json
@@ -1,4 +1,4 @@
 {
-  "DOMAIN": "chike.xyz",
+  "DOMAIN": "{GitHubUserName}.github.io",
   "REPOSITORY": "did-web-on-gh-pages"
 }
\ No newline at end of file
diff --git a/src/generate.js b/src/generate.js
index bd62e3f..9400e69 100644
--- a/src/generate.js
+++ b/src/generate.js
@@ -1,9 +1,23 @@
 const jose = require('jose');
 const fs = require('fs');
+const readlineSync = require('readline-sync');
 
 // Setting
 const CONFIG = require('./config.json');
+const { exit } = require('process');
 
+// Validate Config
+if (CONFIG.DOMAIN == '{GitHubUserName}.github.io') {
+  console.log(`ERROR: Domain in config.json is default ({GitHubUserName}.github.io). Please set your domain.`)
+  exit(1);
+}
+
+if (CONFIG.REPOSITORY == 'did-web-on-gh-pages') {
+  console.log(`WARN: Domain in config.json is default (did-web-on-gh-pages).`);
+  if (!readlineSync.keyInYN(`Is the repository name correct?`)) {
+    exit(1);
+  }
+}
 
 // Templates
 const DID = `did:web:${CONFIG.DOMAIN}:${CONFIG.REPOSITORY}`;