Step 1: Upload (or replace) the ipn.php file in the root directory of your FOSSBilling installation:
FOSSBilling_Path/ipn.php
Step 2: Copy the entire UddoktaPay folder into the following directory:
FOSSBilling_Path/library/Payment/Adapter
Your directory structure should look like this:
FOSSBilling_Path/library/Payment/Adapter/UddoktaPay/UddoktaPay.php
FOSSBilling_Path/library/Payment/Adapter/UddoktaPay/UddoktaPay.png
That’s it! Your UddoktaPay integration for FOSSBilling is now ready to use.