1.  Before  Install this extension you must check the following file

     File path: admin>>controller>>marketplace>>install.php

     Goto line no : 124  and add the below values inside the array $allowed

'system/engine/',
'catalog/controller/',
'catalog/controller/feed',
'catalog/controller/rest',
'catalog/view/theme/default/template/extension/module'    

2.  Procedure to install extension:

    (Download our  mobile_api.ocmod.zip from code & extension folder) 

• Login to the Opencart Admin Panel

• Choose Extension->Installer from the Left Side Menu

• Upload the mobile_api.ocmod.zip

• Choose Extension->Modification from the Left Side Menu

• Click refresh button at the Top right corner

• Choose Extensions->Extension Left Side Menu
  

• Click on the “Choose the extension type” select Box

• Choose the “Module” option

• Find “Shopping Cart Rest API” click Green Color (+) Install Button (Note: Confirm once Shopping Cart Rest API is selected)

• 
  

• Then Click Blue Color Edit Button

• Select Enable Status

• Give any IP Address (EX: 127.0.0.1)

• Click Generate Key Button

 (This will generate key. place this key in Android Application path  app>src>main>java>com.iamretailer>common>appconstants.java value variable and change the domain with your domain)     

• Click the Save button at the Top Right Corner

• Choose Systems->Users->API Left Side Menu

• Click Blue color + symbol add button

• Give API User Name: x-oc-merchant-id

• Click Generate Button

• Choose Status as enable

• Select IP Address Tab, Give any Ip Address just give 1 enough

• Click Save Button Top Right Corner. 

•  You have been successfully installed the mobile extension and app connected with your application.