Unfortunately, it appears that Raygun does not have a ready built deployment integration for ADO. It looks like there are a few supported tools listed here: Supported Deployment Tools , but sadly, no love for ADO. What is this, like 2013?
Anyway, not to worry, Raygun helpfully provides a simple API that we can use to submit a deployment when a release pipeline runs in ADO.
First step is to get an API key from Raygun. Click on your user in the top right and go to My Settings.