Jess Pomfret shows us how we can use dbatools to test Availability Group read-only routing:
The other part I needed to set up was read-only routing, this enables SQL Server to reroute those read only connections to the appropriate replica. You can also list the read only replicas by priority if you have multiple available or you can group them to enable load-balancing.
Although this seems to be setup correctly so that connections that specify their application intent of read only will be routed to the secondary node I wanted to prove it.
Read on to see how Jess is able to prove it.