Using the Process.PluginResult Class

The Process.PluginResult class returns output parameters from the class that implements the interface to the flow.

We recommend using the @InvocableMethod annotation instead of the Process.Plugin interface.

The interface doesn’t support Blob, Collection, and sObject, data types, and it doesn’t support bulk operations. After you implement the interface on a class, the class can be referenced only from flows.
The annotation supports all data types and bulk operations. After you implement the annotation on a class, the class can be referenced from flows, processes, and the Custom Invocable Actions REST API endpoint.
Legacy Apex actions aren’t supported in auto-layout in Flow Builder. Legacy Apex actions are only available to be added in free-form in Flow Builder. Existing actions can be edited in both auto-layout and free-form mode.

Tip

You can instantiate the Process.PluginResult class using one of the following formats:

Process.PluginResult (Map<String,Object>)
Process.PluginResult (String, Object)

Use the map when you have more than one result or when you don't know how many results are returned.

The following is an example of instantiating a Process.PluginResult class.

1string url = 'https://docs.google.com/document/edit?id=abc';
2                String status = 'Success';
3                Map<String,Object> result = new Map<String,Object>();
4                result.put('url', url);
5                result.put('status',status);
6                new Process.PluginResult(result);

Apex Developer Guide

Using the Process.PluginResult Class