DLY1 is a feedback delay.
You can setup your feedback path inside your host using any of the plugins that you want.
In order for this plugin to run you need to add two instances of it in a BUS, set a different group letter per bus and have one instance with Input=On at the top of the bus and one Input=Off at the bottom of the bus. That's all you need to do. Anything that is between the Input and the non-Input version will be the feedback audio path.