diff --git a/.gitignore b/.gitignore
index 894a44c..4ad6467 100644
--- a/.gitignore
+++ b/.gitignore
@@ -102,3 +102,5 @@ venv.bak/
 
 # mypy
 .mypy_cache/
+
+.idea/
\ No newline at end of file
diff --git a/README.md b/README.md
index 7bdf090..e3d915a 100644
--- a/README.md
+++ b/README.md
@@ -14,4 +14,9 @@ certbot certonly --authenticator certbot-dns-hostker:dns-hostker --certbot-dns-h
 ```
 certbot_dns_hostker:dns_hostker_email=[your email]
 certbot_dns_hostker:dns_hostker_token=[your token]
-```
\ No newline at end of file
+```
+
+### Help
+#### Why I can't run successful?
+
+f-string is a feature in Python3.6+, please ensure your python version.
\ No newline at end of file
diff --git a/certbot_dns_hostker/dns_hostker.py b/certbot_dns_hostker/dns_hostker.py
index 162abb6..48b1ab8 100644
--- a/certbot_dns_hostker/dns_hostker.py
+++ b/certbot_dns_hostker/dns_hostker.py
@@ -7,11 +7,23 @@
 from certbot import errors
 from certbot import interfaces
 from certbot.plugins import dns_common
+from ker import Ker
+from ker import HostkerRequestError
 
 logger = logging.getLogger(__name__)
 
 ACCOUNT_URL = 'https://www.hostker.com/'
 
+def sub_domain_to_TLD(domain):
+  domain_list = domain.split('.')[-2:]
+  return '.'.join(domain_list)
+
+def validate_domain_to_record(domain):
+  domain_list = domain.split('.')[:-2]
+  if len(domain_list) > 0 and domain_list[-1] == '*':
+    domain_list = domain_list[:-1]
+  return '.'.join(domain_list)
+
 @zope.interface.implementer(interfaces.IAuthenticator)
 @zope.interface.provider(interfaces.IPluginFactory)
 class Authenticator(dns_common.DNSAuthenticator):
@@ -45,12 +57,14 @@ def _setup_credentials(self):
   
   # add txt record
   def _perform(self, domain, validation_name, validation):
-    record_name = validation_name.split(f'.{domain}')[0]
+    record_name = validate_domain_to_record(validation_name)
+    domain = sub_domain_to_TLD(domain)
     self._get_hostker_client().add_txt_record(domain, record_name, validation, self.ttl)
 
   # delete txt record
   def _cleanup(self, domain, validation_name, validation):
-    record_name = validation_name.split(f'.{domain}')[0]
+    record_name = validate_domain_to_record(validation_name)
+    domain = sub_domain_to_TLD(domain)
     self._get_hostker_client().del_txt_record(domain, record_name)
 
   def _get_hostker_client(self):
@@ -60,57 +74,33 @@ class HostkerClient:
   """Encapsulates all communication with the Hostker API"""
 
   def __init__(self, email, token):
-    self.email = email
-    self.token = token
+    self.ker = Ker(email, token)
     
   
   def add_txt_record(self, domain, record_name, record_content, record_ttl):
-    params = {
-      'domain': domain,
-      'header': record_name,
-      'type': 'TXT',
-      'data': record_content,
-      'ttl': record_ttl,
-      'email': self.email,
-      'token': self.token,
-    }
-
-    r = requests.post('https://i.hostker.com/api/dnsAddRecord', data=params, headers={
-      'Content-Type': 'application/x-www-form-urlencoded'
-    })
-    result = r.json()
-    if result['success'] == 0:
-      raise errors.PluginError(result['errorMessage'])
+    try:
+      self.ker.dns.add(domain=domain, header=record_name, record_type='TXT', data=record_content, ttl=record_ttl)
+    except HostkerRequestError as err:
+      raise errors.PluginError(str(err))
     else:
       logger.debug('Successfully add TXT record')
 
   def del_txt_record(self, domain, record_name):
     record_ids = self._get_record_ids(domain, record_name)
-    for id in record_ids:
-      r = requests.post('https://i.hostker.com/api/dnsDeleteRecord', data={
-        'email': self.email,
-        'token': self.token,
-        'id': id
-      }, headers={
-      'Content-Type': 'application/x-www-form-urlencoded'
-      })
-      result = r.json()
-      if result['success'] == 0:
-        raise errors.PluginError(f'error when delete record: {result["errorMessage"]}')
+    for unique_id in record_ids:
+      try:
+        self.ker.dns.delete(unique_id)
+      except HostkerRequestError as err:
+        raise errors.PluginError(str(err))
       else:
         logger.debug('Successfully remove TXT record')
 
   def _get_record_ids(self, domain, record_name):
-    r = requests.post('https://i.hostker.com/api/dnsGetRecords', data={
-      'email': self.email,
-      'token': self.token,
-      'domain': domain
-    }, headers={
-      'Content-Type': 'application/x-www-form-urlencoded'
-    })
-    result = r.json()
-    if result['success'] == 0:
-      raise errors.PluginError(result['errorMessage'])
-    logger.debug(result)
-    records = list(filter(lambda record: record['header']==record_name and record['type'] == 'TXT', result['records']))
-    return [record['id'] for record in records]
+    try:
+      result = self.ker.dns.list(domain)
+    except HostkerRequestError as err:
+      raise errors.PluginError(str(err))
+    else:
+      logger.debug(result)
+      records = list(filter(lambda record: record['header']==record_name and record['type'] == 'TXT', result['records']))
+      return [record['id'] for record in records]
diff --git a/requirements.txt b/requirements.txt
index 660f14a..10a824b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,3 +9,4 @@ zope.event==4.4
 zope.hookable==4.2.0
 zope.interface==4.6.0
 zope.proxy==4.3.2
+ker.py===0.0.2
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 35a061f..33b2f12 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 
 setup(
   name='certbot-dns-hostker',
-  version='0.0.1',
+  version='0.0.2',
   description='Certbot for Hostker DNS',
   author='SkyAo',
   author_email='csvwolf@qq.com',