# Assign Payment Method By Source and SubSource
The "Assign Payment Method By Source and SubSource" is a macro that runs as an action of the [*Rules Engine*](https://docs.linnworks.com/articles/#!documentation/rules-engine)*.* It is designed to automate the assignment of payment methods to orders based on their specified source and subsource within the Linnworks platform. This macro provides users with a convenient way to streamline payment method assignment, enhancing order processing efficiency.
This guide provides a step-by-step explanation of how to install and set up the macro in Linnworks.
### Start using the macro
There are three steps you need to complete to start using the macro:
1. Install the application.
* Go to *Apps > Application Store > Assign Payment Method >* click Install and follow the on-screen instructions until the installation is complete.
2. Configure the macro.
3. Configure the rule in the *Rules Engine* screen.
#### Configure the macro
Once the *Assign Payment Method* app is installed:
1. Go to *Apps > Macro Configuration* and click + Add new configuration.
2. Select the *Assign Payment Method* macro and click Create Configuration.
3. In the *Macro Configuration* screen, specify the below details and click *Save*:
4. Make sure to enable the macro to continue with the *Rules Engine* configuration.
#### **Functionality:**
1. **Payment Method Assignment:** Automatically assigns payment methods to orders based on their defined source and subsource.
2. **Source and SubSource Matching:** Matches orders with specified source and subsource criteria to ensure accurate payment method assignment.
3. **Payment Method Lookup:** Retrieves available payment methods from the Linnworks platform for selection.
**Usage:**
1. **Input Parameters(In Sequential Order):**
* `OrderIds`: Array of order IDs to process.
* `Source`: Comma-separated list of source values to match against orders.
* `SubSource`: Comma-separated list of subsource values to match against orders.
* `PaymentMethods`: Comma-separated list of payment method names to assign to matching orders.
2. **Execution:**
* Call the macro with the necessary input parameters to initiate the payment method assignment process.
3. **Outcome:**
* The macro iterates through the specified orders and matches them with the provided source and subsource criteria.
* If a match is found, the corresponding payment method from the provided list is assigned to the order.
