Documentation
Installation instructions
You can install extension using Extension Installer or manually. In the latter case unpack and upload all folders from "upload" directory to the root of your store. If there's install.xml file in the package, rename it to extension_name.ocmod.xml, replacing "extension_name" with extension's name (or any other name), and upload it to "system" folder. When upgrading from previous version simply rewrite all existing files. Refresh modifications cache from Extensions -> Modifications page (not needed if install.xml file is not included in the package).
Note for OpenCart 3 users
If you see "The directory is not allowed to be written to" error message, download OpenCart 3.0 Extension Installer Fix from this page and install it. Then install the main extension.
Note for OpenCart 2.0.X users
Sometimes OCMod inserts modification in multiple files, which are separated by "|" character in XML-file. On earlier OpenCart 2 versions a comma was used instead. To quickly fix this, open XML file (usually, install.xml) and replace all occurrences of "|" character with "," for "path" attribute in every applicable <file> element. Search for "<file path=" to quickly find and highlight all elements.
If after installation you have "Permission denied" issue when accessing Modules, Shipping, Payments, Order Totals (or any other) section of Extensions menu, remove "module", "shipping", "payment", "total" (or any other) folder from "admin/controller/extension" directory. Same for "admin/language/en-gb/extension" directory. For example ("module" should be removed from both paths):
admin/controller/extension/module
admin/language/en-gb/extension/module
Permissions
In some cases it is required to manually set permissions for installed extension. To do this go to System -> User Groups, find your group and select access/modify permissions for desired extension. You can find extension in permissions list by folder/filename pair (for example, marketing/acoupon).
Extension Setup
Go to Extensions -> Order Totals, find Category Fee or Discount, setup accordingly and enable.
How to use
If you want to hide product fee and add it to some other total, be sure to set Product Fee or Discount sort order number higher than selected total. For example, if you choose to add product fee to Shipping total, which has Sort Order value set to 5, Product Fee or Discount sort order must be at least 6.
Be careful with "Round by" feature. Setting it to wrong number will cause improper counting of fees.