It is not obvious on the DevTest RabbitMQ Connect asset how to change to a different Virtual Host.
RabbitMQ Server allows for multiple Virtual Hosts to be defined.
DevTest 9.0.0 and later.
Choose the RabbitMQ Connection Asset in your project.config.
Click the second '+' and select 'Virtual Host':
This adds the field to the Asset. The default Virtual Host is already filled as "/", so change it to whatever you need.