Installation document for Royal Mail Click and Drop API for Opencart 2.x
Requirements
Please make sure you have set the correct permissions for the software as in the list below.
Administrator permission for OCMOD(How to use OCMOD Opencart ?) | Important |
FTP settings(How to setup FTP for Opencart?) |
1. Upload
Method 1: Directly upload from only one xxx.ocmod.zip file
Notice: You must extract downloaded zip file to get installation file.The file name must have extension Royal Mail Click and Drop API OC v*.* - v*.*.ocmod.zip,
so you should not change the file name under any circumstances.
Firstly, go to your Opencart admin panel -> Extensions -> Extension installer -> Upload your file -> Continue

Method 2: https://mmosolution.com/blogs/how-to-use-ocmod-opencart-by-FTP-without-extension-installer.html
Secondly, you should go to Modifications -> Click refresh and clear buttons as per image below:
1. Upload
Method 1: Directly upload from only one xxx.ocmod.zip file
Notice: You must extract downloaded zip file to get installation file.The file name must have extension Royal Mail Click and Drop API OC v*.* - v*.*.ocmod.zip,
so you should not change the file name under any circumstances.
Firstly, go to your Opencart admin panel -> Extensions -> Extension installer -> Upload your file -> Continue

Method 2: https://mmosolution.com/blogs/how-to-use-ocmod-opencart-by-FTP-without-extension-installer.html
Secondly, you should go to Modifications -> Click refresh and clear buttons as per image below:
2. Add permission
Login to your Opencart admin panel and go to System → Users → User Group
Click edit your user group name (Generally, default user group name is Administrator as Image 2
Image 2
Next, check access permission, modify permission for [extension name] as image 2.1
- module/RoyalMailC2DAPI
3. Installation
Go to Extensions → Modules Find Royal Mail Click and Drop API and click install as image 3
4. Configuration
Congratulations!
[extension name] is now installed and configured. You can access it from Extensions > module > Royal Mail Click and Drop API then click [ Edit ]
5. Configure & Enjoy your new MMOS extension!
5. Configure& Enjoy new extension