diff --git a/README.md b/README.md
index db3181a..0a8232b 100644
--- a/README.md
+++ b/README.md
@@ -36,12 +36,12 @@ return [
     /**
      * The length of token.
      */
-    'digits'    => env('OTPIFY_DIGITS', 6),
+    'digits'    => 6,
 
     /**
      * The expiry time of token in minutes.
      */
-    'validity'  => env('OTPIFY_VALIDITY', 15)
+    'validity'  => 15
 ];
 ```
 
diff --git a/composer.json b/composer.json
index d062b6e..103b0e5 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,14 @@
     ],
     "minimum-stability": "dev",
     "require": {
-        "php": ">=7.4.0"
+        "php": "^8.0",
+        "illuminate/console": "^9.0",
+        "illuminate/database": "^9.0",
+        "illuminate/support": "^9.0",
+        "nesbot/carbon": "^2.35"
+    },
+    "require-dev": {
+        "illuminate/config": "^9.0"
     },
     "config": {
         "optimize-autoloader": true,
diff --git a/config/otpify.php b/config/otpify.php
index 11ed888..3c1ceba 100644
--- a/config/otpify.php
+++ b/config/otpify.php
@@ -4,10 +4,10 @@
     /**
      * The length of token.
      */
-    'digits'    => env('OTPIFY_DIGITS', 6),
+    'digits'    => 6,
 
     /**
      * The expiry time of token in minutes.
      */
-    'validity'  => env('OTPIFY_VALIDITY', 15)
+    'validity'  => 15
 ];
diff --git a/src/Facades/Otpify.php b/src/Facades/Otpify.php
index 3d4c893..167a8a0 100644
--- a/src/Facades/Otpify.php
+++ b/src/Facades/Otpify.php
@@ -4,6 +4,10 @@
 
 use Illuminate\Support\Facades\Facade;
 
+/**
+ * @method static array generate(string $identifier, int $userId = null, string $otpType = null, int $digits = null, int $validity = null)
+ * @method static array validate(string $identifier, string $token, string $otpType = null)
+ */
 class Otpify extends Facade
 {
     /**
diff --git a/src/Otpify.php b/src/Otpify.php
index e744326..50a427c 100644
--- a/src/Otpify.php
+++ b/src/Otpify.php
@@ -20,15 +20,20 @@ class Otpify
      */
     public static function generate(string $identifier, int $userId = null, string $otpType = null, int $digits = null, int $validity = null)
     {
-        if ($digits === null) $digits = config('otpify.digits');
-        if ($validity === null) $validity = config('otpify.validity');
+        if ($digits === null) {
+            $digits = config('otpify.digits');
+        }
+
+        if ($validity === null) {
+            $validity = config('otpify.validity');
+        }
 
         Otp::where([
             ['identifier', $identifier],
             ['otp_type', $otpType]
         ])->delete();
 
-        if (($digits >= 4) && ($digits <= 8)) {
+        if (($digits >= 4) && ($digits <= 12)) {
             $token = rand(pow(10, $digits - 1), pow(10, $digits) - 1);
 
             Otp::create([
@@ -38,13 +43,13 @@ public static function generate(string $identifier, int $userId = null, string $
                 'validity'          => $validity,
                 'otp_type'          => $otpType
             ]);
-        }
 
-        return [
-            'status'    => 'success',
-            'token'     => $token,
-            'message'   => 'OTP genetated successfully'
-        ];
+            return [
+                'status'    => 'success',
+                'token'     => $token,
+                'message'   => 'OTP genetated successfully'
+            ];
+        }
     }
 
     /**
diff --git a/src/OtpifyServiceProvider.php b/src/OtpifyServiceProvider.php
index f6fbb39..a42e8d3 100644
--- a/src/OtpifyServiceProvider.php
+++ b/src/OtpifyServiceProvider.php
@@ -2,8 +2,9 @@
 
 namespace PrasanthJ\Otpify;
 
-use PrasanthJ\Otpify\Commands\CleanOtps;
 use Illuminate\Support\ServiceProvider;
+use PrasanthJ\Otpify\Commands\CleanOtps;
+use PrasanthJ\Otpify\Otpify;
 
 class OtpifyServiceProvider extends ServiceProvider
 {
@@ -14,7 +15,7 @@ class OtpifyServiceProvider extends ServiceProvider
      */
     public function register()
     {
-        $this->app->bind('Otpify', \PrasanthJ\Otpify\Otpify::class);
+        $this->app->bind('Otpify', Otpify::class);
     }
 
     /**