How to Find Bing/Microsoft Event Action and Category

Step 1: Login to Bing Ads

Step 2: Navigate to Conversion Goals

Go to Conversions > Conversion Goals.

Step 3: Select your Conversion

Step 4: Navigate to the Set up Tagging Step

You'll find the Event Action and Category in the Set Up Tagging step. In my example below, my Action is "Purchase" and Category is "checkout".